TY - JOUR
A1 - Lu, Yuan
A1 - Boswell, Wiliam
A1 - Boswell, Mikki
A1 - Klotz, Barbara
A1 - Kneitz, Susanne
A1 - Regneri, Janine
A1 - Savage, Markita
A1 - Mendoza, Cristina
A1 - Postlethwait, John
A1 - Warren, Wesley C.
A1 - Schartl, Manfred
A1 - Walter, Ronald B.
T1 - Application of the Transcriptional Disease Signature (TDSs) to Screen Melanoma-Effective Compounds in a Small Fish Model
JF - Scientific Reports
N2 - Cell culture and protein target-based compound screening strategies, though broadly utilized in selecting candidate compounds, often fail to eliminate candidate compounds with non-target effects and/or safety concerns until late in the drug developmental process. Phenotype screening using intact research animals is attractive because it can help identify small molecule candidate compounds that have a high probability of proceeding to clinical use. Most FDA approved, first-in-class small molecules were identified from phenotypic screening. However, phenotypic screening using rodent models is labor intensive, low-throughput, and very expensive. As a novel alternative for small molecule screening, we have been developing gene expression disease profiles, termed the Transcriptional Disease Signature (TDS), as readout of small molecule screens for therapeutic molecules. In this concept, compounds that can reverse, or otherwise affect known disease-associated gene expression patterns in whole animals may be rapidly identified for more detailed downstream direct testing of their efficacy and mode of action. To establish proof of concept for this screening strategy, we employed a transgenic strain of a small aquarium fish, medaka (Oryzias latipes), that overexpresses the malignant melanoma driver gene xmrk, a mutant egfr gene, that is driven by a pigment cell-specific mitf promoter. In this model, melanoma develops with 100% penetrance. Using the transgenic medaka malignant melanoma model, we established a screening system that employs the NanoString nCounter platform to quantify gene expression within custom sets of TDS gene targets that we had previously shown to exhibit differential transcription among xmrk-transgenic and wild-type medaka. Compound-modulated gene expression was identified using an internet-accessible custom-built data processing pipeline. The effect of a given drug on the entire TDS profile was estimated by comparing compound-modulated genes in the TDS using an activation Z-score and Kolmogorov-Smirnov statistics. TDS gene probes were designed that target common signaling pathways that include proliferation, development, toxicity, immune function, metabolism and detoxification. These pathways may be utilized to evaluate candidate compounds for potential favorable, or unfavorable, effects on melanoma-associated gene expression. Here we present the logistics of using medaka to screen compounds, as well as, the development of a user-friendly NanoString data analysis pipeline to support feasibility of this novel TDS drug-screening strategy.
KW - bioinformatics
KW - phenotypic screening
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237322
VL - 9
ER -
TY - JOUR
A1 - Boetzl, Fabian A.
A1 - Konle, Antonia
A1 - Krauss, Jochen
T1 - Aphid cards – useful model for assessing predation rates or bias prone nonsense?
JF - Journal of Applied Entomology
N2 - Predation on pest organisms is an essential ecosystem function supporting yields in modern agriculture. However, assessing predation rates is intricate, and they can rarely be linked directly to predator densities or functions. We tested whether sentinel prey aphid cards are useful tools to assess predation rates in the field. Therefore, we looked at aphid cards of different sizes on the ground level as well as within the vegetation. Additionally, by trapping ground‐dwelling predators, we examined whether obtained predation rates could be linked to predator densities and traits. Predation rates recorded with aphid cards were independent of aphid card size. However, predation rates on the ground level were three times higher than within the vegetation. We found both predatory carabid activity densities as well as community weighted mean body size to be good predictors for predation rates. Predation rates obtained from aphid cards are stable over card type and related to predator assemblages. Aphid cards, therefore, are a useful, efficient method for rapidly assessing the ecosystem function predation. Their use might especially be recommended for assessments on the ground level and when time and resource limitations rule out more elaborate sentinel prey methods using exclosures with living prey animals.
KW - carabid beetles
KW - ecosystem service
KW - ground-dwelling predators
KW - methods
KW - natural pest control
KW - sentinel prey
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204798
VL - 144
IS - 1-2
ER -
TY - JOUR
A1 - Otto, Christoph
A1 - Hahlbrock, Theresa
A1 - Eich, Kilian
A1 - Karaaslan, Ferdi
A1 - Jürgens, Constantin
A1 - Germer, Christoph-Thomas
A1 - Wiegering, Armin
A1 - Kämmerer, Ulrike
T1 - Antiproliferative and antimetabolic effects behind the anticancer property of fermented wheat germ extract
JF - BMC Complementary and Alternative Medicine
N2 - Background
Fermented wheat germ extract (FWGE) sold under the trade name Avemar exhibits anticancer activity in vitro and in vivo. Its mechanisms of action are divided into antiproliferative and antimetabolic effects. Its influcence on cancer cell metabolism needs further investigation. One objective of this study, therefore, was to further elucidate the antimetabolic action of FWGE. The anticancer compound 2,6-dimethoxy-1,4-benzoquinone (DMBQ) is the major bioactive compound in FWGE and is probably responsible for its anticancer activity. The second objective of this study was to compare the antiproliferative properties in vitro of FWGE and the DMBQ compound.
Methods
The IC\(_{50}\) values of FWGE were determined for nine human cancer cell lines after 24 h of culture. The DMBQ compound was used at a concentration of 24 μmol/l, which is equal to the molar concentration of DMBQ in FWGE. Cell viability, cell cycle, cellular redox state, glucose consumption, lactic acid production, cellular ATP levels, and the NADH/NAD\(^+\) ratio were measured.
Results
The mean IC\(_{50}\) value of FWGE for the nine human cancer cell lines tested was 10 mg/ml. Both FWGE (10 mg/ml) and the DMBQ compound (24 μmol/l) induced massive cell damage within 24 h after starting treatment, with changes in the cellular redox state secondary to formation of intracellular reactive oxygen species. Unlike the DMBQ compound, which was only cytotoxic, FWGE exhibited cytostatic and growth delay effects in addition to cytotoxicity. Both cytostatic and growth delay effects were linked to impaired glucose utilization which influenced the cell cycle, cellular ATP levels, and the NADH/NAD\(^+\) ratio. The growth delay effect in response to FWGE treatment led to induction of autophagy.
Conclusions
FWGE and the DMBQ compound both induced oxidative stress-promoted cytotoxicity. In addition, FWGE exhibited cytostatic and growth delay effects associated with impaired glucose utilization which led to autophagy, a possible previously unknown mechanism behind the influence of FWGE on cancer cell metabolism.
KW - cytostatic
KW - FWGE
KW - benzoquinone
KW - cancer cells
KW - reactive oxygen species
KW - autophagy
KW - cytotoxicity
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146013
VL - 16
IS - 160
ER -
TY - JOUR
A1 - Bona, Marion
A1 - Scheer, Ulrich
A1 - Bautz, Ekkehard K. F.
T1 - Antibodies to RNA polymerase II (B) inhibit transcription in lampbrush chromosomes after microinjection into living amphibian oocytes
N2 - Antibodies directed against RNA polymerase II (B) from Drosophila melanogaster were obtained from rabbit sera and, as monoclonal immunoglobulins, from mouse hybridomas and shown to cross-react with the amphibian enzyme protein. Localization by indirect immunofluorescence microscopy revealed the association of this enzyme with chromatin of interphase nuclei of amphibian cells and its absence in nucleoli. Purified immunoglobulins were microinjected in to nuclei ofliving vitellogenic oocytes of Ple1lrodeles waltlii and X enopus laevis and their effects on transcriptional processes were monitored by biochemical and light and electron microscopic stud ies. RNA polymerase II antibodies from rabbit sera caused a rapid and almost complete release of nascent transcripts from the chromatin axis of the loops of lampbrush chromosomes, followed by collapse of the loops and their retraction on the main chromosome axis. Monoclonal murine antibodies to the Iarge RNA polymerase II subunits also inhibited transcription in chromosome Ioops but appeared to inhibit initiation rather than elongation events. Activities of class land III RNA polymerases were not significantly affected by injection of antibodies to polymerase II, indicating immunological differences between the three RNA polymerases. The potential value of the in vitro test system described , as a very sensitive assay for detecting proteins involved in transcription in living cells, is discussed. 1
Y1 - 1981
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33128
ER -
TY - JOUR
A1 - Colizzi, Francesca Sara
A1 - Beer, Katharina
A1 - Cuti, Paolo
A1 - Deppisch, Peter
A1 - Martínez Torres, David
A1 - Yoshii, Taishi
A1 - Helfrich-Förster, Charlotte
T1 - Antibodies Against the Clock Proteins Period and Cryptochrome Reveal the Neuronal Organization of the Circadian Clock in the Pea Aphid
JF - Frontiers in Physiology
N2 - Circadian clocks prepare the organism to cyclic environmental changes in light, temperature, or food availability. Here, we characterized the master clock in the brain of a strongly photoperiodic insect, the aphid Acyrthosiphon pisum, immunohistochemically with antibodies against A. pisum Period (PER), Drosophila melanogaster Cryptochrome (CRY1), and crab Pigment-Dispersing Hormone (PDH). The latter antibody detects all so far known PDHs and PDFs (Pigment-Dispersing Factors), which play a dominant role in the circadian system of many arthropods. We found that, under long days, PER and CRY are expressed in a rhythmic manner in three regions of the brain: the dorsal and lateral protocerebrum and the lamina. No staining was detected with anti-PDH, suggesting that aphids lack PDF. All the CRY1-positive cells co-expressed PER and showed daily PER/CRY1 oscillations of high amplitude, while the PER oscillations of the CRY1-negative PER neurons were of considerable lower amplitude. The CRY1 oscillations were highly synchronous in all neurons, suggesting that aphid CRY1, similarly to Drosophila CRY1, is light sensitive and its oscillations are synchronized by light-dark cycles. Nevertheless, in contrast to Drosophila CRY1, aphid CRY1 was not degraded by light, but steadily increased during the day and decreased during the night. PER was always located in the nuclei of the clock neurons, while CRY was predominantly cytoplasmic and revealed the projections of the PER/CRY1-positive neurons. We traced the PER/CRY1-positive neurons through the aphid protocerebrum discovering striking similarities with the circadian clock of D. melanogaster: The CRY1 fibers innervate the dorsal and lateral protocerebrum and putatively connect the different PER-positive neurons with each other. They also run toward the pars intercerebralis, which controls hormone release via the neurohemal organ, the corpora cardiaca. In contrast to Drosophila, the CRY1-positive fibers additionally travel directly toward the corpora cardiaca and the close-by endocrine gland, corpora allata. This suggests a direct link between the circadian clock and the photoperiodic control of hormone release that can be studied in the future.
KW - aphids
KW - circadian clock
KW - cryptochrome
KW - period
KW - hemiptera
KW - insects
KW - photoperiodism
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242909
SN - 1664-042X
VL - 12
ER -
TY - JOUR
A1 - Minden, Vanessa
A1 - Schnetger, Bernhard
A1 - Pufal, Gesine
A1 - Leonhardt, Sara D.
T1 - Antibiotic-induced effects on scaling relationships and on plant element contents in herbs and grasses
JF - Ecology and Evolution
N2 - Plant performance is correlated with element concentrations in plant tissue, which may be impacted by adverse chemical soil conditions. Antibiotics of veterinary origin can adversely affect plant performance. They are released to agricultural fields via grazing animals or manure, taken up by plants and may be stored, transformed or sequestered by plant metabolic processes. We studied the potential effects of three antibiotics (penicillin, sulfadiazine, and tetracycline) on plant element contents (macro- and microelements). Plant species included two herb species (Brassica napus and Capsella bursa-pastoris) and two grass species (Triticum aestivum and Apera spica-venti), representing two crop species and two noncrop species commonly found in field margins, respectively. Antibiotic concentrations were chosen as to reflect in vivo situations, that is, relatively low concentrations similar to those detected in soils. In a greenhouse experiment, plants were raised in soil spiked with antibiotics. After harvest, macro- and microelements in plant leaves, stems, and roots were determined (mg/g). Results indicate that antibiotics can affect element contents in plants. Penicillin exerted the greatest effect both on element contents and on scaling relationships of elements between plant organs. Roots responded strongest to antibiotics compared to stems and leaves. We conclude that antibiotics in the soil, even in low concentrations, lead to low-element homeostasis, altering the scaling relationships between roots and other plant organs, which may affect metabolic processes and ultimately the performance of a plant.
KW - antibiotics
KW - homeostasis
KW - scaling relationships
KW - standardized major axis regression
KW - tissue nutrient contents
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224094
VL - 8
ER -
TY - JOUR
A1 - Beier, Hildburg
A1 - Gätschenberger, Heike
A1 - Azzami, Klara
A1 - Tautz, Jürgen
T1 - Antibacterial Immune Competence of Honey Bees (Apis mellifera) Is Adapted to Different Life Stages and Environmental Risks
JF - PLoS ONE
N2 - The development of all honey bee castes proceeds through three different life stages all of which encounter microbial infections to a various extent. We have examined the immune strength of honey bees across all developmental stages with emphasis on the temporal expression of cellular and humoral immune responses upon artificial challenge with viable Escherichia coli bacteria. We employed a broad array of methods to investigate defence strategies of infected individuals: (a) fate of bacteria in the haemocoel; (b) nodule formation and (c) induction of antimicrobial peptides (AMPs). Newly emerged adult worker bees and drones were able to activate efficiently all examined immune reactions. The number of viable bacteria circulating in the haemocoel of infected bees declined rapidly by more than two orders of magnitude within the first 4–6 h post-injection (p.i.), coinciding with the occurrence of melanised nodules. Antimicrobial activity, on the other hand, became detectable only after the initial bacterial clearance. These two temporal patterns of defence reactions very likely represent the constitutive cellular and the induced humoral immune response. A unique feature of honey bees is that a fraction of worker bees survives the winter season in a cluster mostly engaged in thermoregulation. We show here that the overall immune strength of winter bees matches that of young summer bees although nodulation reactions are not initiated at all. As expected, high doses of injected viable E.coli bacteria caused no mortality in larvae or adults of each age. However, drone and worker pupae succumbed to challenge with E.coli even at low doses, accompanied by a premature darkening of the pupal body. In contrast to larvae and adults, we observed no fast clearance of viable bacteria and no induction of AMPs but a rapid proliferation of E.coli bacteria in the haemocoel of bee pupae ultimately leading to their death.
KW - escherichia coli infections
KW - honey bees
KW - bees
KW - antimicrobials
KW - bacterial pathogens
KW - larvae
KW - pupae
KW - winter
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96895
ER -
TY - JOUR
A1 - Becam, Jérôme
A1 - Walter, Tim
A1 - Burgert, Anne
A1 - Schlegel, Jan
A1 - Sauer, Markus
A1 - Seibel, Jürgen
A1 - Schubert-Unkmeir, Alexandra
T1 - Antibacterial activity of ceramide and ceramide analogs against pathogenic Neisseria
JF - Scientific Reports
N2 - Certain fatty acids and sphingoid bases found at mucosal surfaces are known to have antibacterial activity and are thought to play a more direct role in innate immunity against bacterial infections. Herein, we analysed the antibacterial activity of sphingolipids, including the sphingoid base sphingosine as well as short-chain C\(_{6}\) and long-chain C\(_{16}\)-ceramides and azido-functionalized ceramide analogs against pathogenic Neisseriae. Determination of the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) demonstrated that short-chain ceramides and a ω-azido-functionalized C\(_{6}\)-ceramide were active against Neisseria meningitidis and N. gonorrhoeae, whereas they were inactive against Escherichia coli and Staphylococcus aureus. Kinetic assays showed that killing of N. meningitidis occurred within 2 h with ω–azido-C\(_{6}\)-ceramide at 1 X the MIC. Of note, at a bactericidal concentration, ω–azido-C\(_{6}\)-ceramide had no significant toxic effect on host cells. Moreover, lipid uptake and localization was studied by flow cytometry and confocal laser scanning microscopy (CLSM) and revealed a rapid uptake by bacteria within 5 min. CLSM and super-resolution fluorescence imaging by direct stochastic optical reconstruction microscopy demonstrated homogeneous distribution of ceramide analogs in the bacterial membrane. Taken together, these data demonstrate the potent bactericidal activity of sphingosine and synthetic short-chain ceramide analogs against pathogenic Neisseriae.
KW - ceramide analogs
KW - Neisseria
KW - ceramide
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159367
VL - 7
ER -
TY - JOUR
A1 - Doppler, Kathrin
A1 - Schuster, Yasmin
A1 - Appeltshauser, Luise
A1 - Biko, Lydia
A1 - Villmann, Carmen
A1 - Weishaupt, Andreas
A1 - Werner, Christian
A1 - Sommer, Claudia
T1 - Anti-CNTN1 IgG3 induces acute conduction block and motor deficits in a passive transfer rat model
JF - Journal of Neuroinflammation
N2 - Background:
Autoantibodies against the paranodal protein contactin-1 have recently been described in patients with severe acute-onset autoimmune neuropathies and mainly belong to the IgG4 subclass that does not activate complement. IgG3 anti-contactin-1 autoantibodies are rare, but have been detected during the acute onset of disease in some cases. There is evidence that anti-contactin-1 prevents adhesive interaction, and chronic exposure to anti-contactin-1 IgG4 leads to structural changes at the nodes accompanied by neuropathic symptoms. However, the pathomechanism of acute onset of disease and the pathogenic role of IgG3 anti-contactin-1 is largely unknown.
Methods:
In the present study, we aimed to model acute autoantibody exposure by intraneural injection of IgG of patients with anti-contacin-1 autoantibodies to Lewis rats. Patient IgG obtained during acute onset of disease (IgG3 predominant) and IgG from the chronic phase of disease (IgG4 predominant) were studied in comparison.
Results:
Conduction blocks were measured in rats injected with the “acute” IgG more often than after injection of “chronic” IgG (83.3% versus 35%) and proved to be reversible within a week after injection. Impaired nerve conduction was accompanied by motor deficits in rats after injection of the “acute” IgG but only minor structural changes of the nodes. Paranodal complement deposition was detected after injection of the “acute IgG”. We did not detect any inflammatory infiltrates, arguing against an inflammatory cascade as cause of damage to the nerve. We also did not observe dispersion of paranodal proteins or sodium channels to the juxtaparanodes as seen in patients after chronic exposure to anti-contactin-1.
Conclusions:
Our data suggest that anti-contactin-1 IgG3 induces an acute conduction block that is most probably mediated by autoantibody binding and subsequent complement deposition and may account for acute onset of disease in these patients. This supports the notion of anti-contactin-1-associated neuropathy as a paranodopathy with the nodes of Ranvier as the site of pathogenesis.
KW - complement deposition
KW - paranodopathy
KW - anti-contactin-1
KW - CIDP
KW - passive transfer
KW - autoantibody
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200476
VL - 16
IS - 73
ER -
TY - JOUR
A1 - Wohlwend, Michael R.
A1 - Craven, Dylan
A1 - Weigelt, Patrick
A1 - Seebens, Hanno
A1 - Winter, Marten
A1 - Kreft, Holger
A1 - Zurell, Damaris
A1 - Sarmento Cabral, Juliano
A1 - Essl, Franz
A1 - van Kleunen, Mark
A1 - Pergl, Jan
A1 - Pyšek, Petr
A1 - Knight, Tiffany M.
T1 - Anthropogenic and environmental drivers shape diversity of naturalized plants across the Pacific
JF - Diversity and Distributions
N2 - Aim
The Pacific exhibits an exceptional number of naturalized plant species, but the drivers of this high diversity and the associated compositional patterns remain largely unknown. Here, we aim to (a) improve our understanding of introduction and establishment processes and (b) evaluate whether this information is sufficient to create scientific conservation tools, such as watchlists.
Location
Islands in the Pacific Ocean, excluding larger islands such as New Zealand, Japan, the Philippines and Indonesia.
Methods
We combined information from the most up‐to‐date data sources to quantify naturalized plant species richness and turnover across island groups and investigate the effects of anthropogenic, biogeographic and climate drivers on these patterns. In total, we found 2,672 naturalized plant species across 481 islands and 50 island groups, with a total of 11,074 records.
Results
Most naturalized species were restricted to few island groups, and most island groups have a low number of naturalized species. Island groups with few naturalized species were characterized by a set of widespread naturalized species. Several plant families that contributed many naturalized species globally also did so in the Pacific, particularly Fabaceae and Poaceae. However, many families were significantly over‐ or under‐represented in the Pacific naturalized flora compared to other regions of the world. Naturalized species richness increased primarily with increased human activity and island altitude/area, whereas similarity between island groups in temperature along with richness differences was most important for beta diversity.
Main conclusions
The distribution and richness of naturalized species can be explained by a small set of drivers. The Pacific region contains many naturalized plant species also naturalized in other regions in the world, but our results highlight key differences such as a stronger role of anthropogenic drivers in shaping diversity patterns. Our results establish a basis for predicting and preventing future naturalizations in a threatened biodiversity hotspot.
KW - anthropogenic drivers
KW - beta diversity
KW - island biogeography
KW - naturalized species
KW - Pacific Ocean
KW - plant invasion
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239925
VL - 27
IS - 6
SP - 1120
EP - 1133
ER -
TY - JOUR
A1 - Stieb, Sara Mae
A1 - Kelber, Christina
A1 - Wehner, Rüdiger
A1 - Rössler, Wolfgang
T1 - Antennal-Lobe Organization in Desert Ants of the Genus Cataglyphis
JF - Brain, Behavior and Evolution
N2 - Desert ants of the genus Cataglyphis possess remarkable visual navigation capabilities. Although Cataglyphis species lack a trail pheromone system, Cataglyphis fortis employs olfactory cues for detecting nest and food sites. To investigate potential adaptations in primary olfactory centers of the brain of C. fortis, we analyzed olfactory glomeruli (odor processing units) in their antennal lobes and compared them to glomeruli in different Cataglyphis species. Using confocal imaging and 3D reconstruction, we analyzed the number, size and spatial arrangement of olfactory glomeruli in C. fortis, C.albicans, C.bicolor, C.rubra, and C.noda. Workers of all Cataglyphis species have smaller numbers of glomeruli (198–249) compared to those previously found in olfactory-guided ants. Analyses in 2 species of Formica – a genus closely related to Cataglyphis – revealed substantially higher numbers of olfactory glomeruli (c. 370), which is likely to reflect the importance of olfaction in these wood ant species. Comparisons between Cataglyphis species revealed 2 special features in C. fortis. First, with c. 198 C. fortis has the lowest number of glomeruli compared to all other species. Second, a conspicuously enlarged glomerulus is located close to the antennal nerve entrance. Males of C. fortis possess a significantly smaller number of glomeruli (c. 150) compared to female workers and queens. A prominent male-specific macroglomerulus likely to be involved in sex pheromone communication occupies a position different from that of the enlarged glomerulus in females. The behavioral significance of the enlarged glomerulus in female workers remains elusive. The fact that C. fortis inhabits microhabitats (salt pans) that are avoided by all other Cataglyphis species suggests that extreme ecological conditions may not only have resulted in adaptations of visual capabilities, but also in specializations of the olfactory system.
KW - olfactory glomeruli
KW - plasticity
KW - ant
KW - antennal lobe
KW - glomerulus
KW - insects
KW - interspecific comparison
KW - macroglomerulus
KW - olfaction
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196815
SN - 0006-8977
SN - 1421-9743
N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL - 77
IS - 3
ER -
TY - JOUR
A1 - Kim, Bo-Mi
A1 - Amores, Angel
A1 - Kang, Seunghyun
A1 - Ahn, Do-Hwan
A1 - Kim, Jin-Hyoung
A1 - Kim, Il-Chan
A1 - Lee, Jun Hyuck
A1 - Lee, Sung Gu
A1 - Lee, Hyoungseok
A1 - Lee, Jungeun
A1 - Kim, Han-Woo
A1 - Desvignes, Thomas
A1 - Batzel, Peter
A1 - Sydes, Jason
A1 - Titus, Tom
A1 - Wilson, Catherine A.
A1 - Catchen, Julian M.
A1 - Warren, Wesley C.
A1 - Schartl, Manfred
A1 - Detrich, H. William III
A1 - Postlethwait, John H.
A1 - Park, Hyun
T1 - Antarctic blackfin icefish genome reveals adaptations to extreme environments
JF - Nature Ecology & Evolution
N2 - Icefishes (suborder Notothenioidei; family Channichthyidae) are the only vertebrates that lack functional haemoglobin genes and red blood cells. Here, we report a high-quality genome assembly and linkage map for the Antarctic blackfin icefish Chaenocephalus aceratus, highlighting evolved genomic features for its unique physiology. Phylogenomic analysis revealed that Antarctic fish of the teleost suborder Notothenioidei, including icefishes, diverged from the stickleback lineage about 77 million years ago and subsequently evolved cold-adapted phenotypes as the Southern Ocean cooled to sub-zero temperatures. Our results show that genes involved in protection from ice damage, including genes encoding antifreeze glycoprotein and zona pellucida proteins, are highly expanded in the icefish genome. Furthermore, genes that encode enzymes that help to control cellular redox state, including members of the sod3 and nqo1 gene families, are expanded, probably as evolutionary adaptations to the relatively high concentration of oxygen dissolved in cold Antarctic waters. In contrast, some crucial regulators of circadian homeostasis (cry and per genes) are absent from the icefish genome, suggesting compromised control of biological rhythms in the polar light environment. The availability of the icefish genome sequence will accelerate our understanding of adaptation to extreme Antarctic environments.
KW - animal physiology
KW - evolutionary genetics
KW - genomics
KW - ichthyology
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-325811
VL - 3
ER -
TY - JOUR
A1 - Müller, T.
A1 - Sebald, Walter
A1 - Oschkinat, H.
T1 - Antagonist design through forced electrostatic mismatch
N2 - No abstract available
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62408
ER -
TY - JOUR
A1 - Scheer, Ulrich
A1 - Franke, Werner W.
T1 - Annulate lamellae in plant cells: formation during microsporogenesis and pollen development in Canna generalis Bailey
N2 - The occurrence of stacked annulate tamellae is documented for a plant cell system, namely for pollen mother cells and developing pollen grains of Canna generalis. Their structural subarchiteeture and relationship to endoplasmie reticulum (ER) and nuclear envelope cisternae is described in detail. The results demonstrate structural homology between plant and animal annulate lamellae and are compatible with, though do not prove, the view that annulate lamcllar cisternae may originate as a degenerative form of endoplasmic retieulum.
Y1 - 1972
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32160
ER -
TY - JOUR
A1 - Linsenmair, Karl Eduard
T1 - Anemomenotactic orientation in beetles and scorpions
N2 - Scorpions, living in North African semideserts are - in spite of disrupting experimental interferences - able to maintain a certain direction in their natural environment in the dark on a plane surface. Under comparable laboratory conditions, excluding the possibility of light or gravity orientation, they can orient themselves if a directed air current passes over the "arena." In most cases the scorpions do not run necessarily with or against the wind, but rather maintain constant angles to the air current for anywhere from minutes to many hours. They are running anemomenotactically (ref. 1). Under identical conditions many species of beetles also orient themselves to air currents (refs. 2 to 4). The main problems to be solved in the study of anemomenotactic orientation are: (1) Which physical qualities of the air current have an influence on the anemomenotaxis? (2) With which sense organs do beetles and scorpions perceive wind directions? (3) Which physiological mechanism is the basis of anemomenotactic orientation? (4) What is the biological significance of anemomenotaxis in beetles and scorpions? With respect to these problems, more study has been done on beetles than on scorpions. Therefore, due to lack of space, I shall discuss mainly some of the results obtained in experiments with dung beetles (Geotrupes silvaticus, G. ,Stercorarius, G. armifrons, G. niger, Scarabaeus variolosus) and tenebrionid beetles (Tenebrio molitor, Pimelia grossa, P. tenuicomis, Scaurus dubius).
KW - Biologie
KW - Skorpion
KW - Käfer
Y1 - 1972
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78118
ER -
TY - JOUR
A1 - Brehm, Klaus
A1 - Koziol, Uriel
A1 - Krohne, Georg
T1 - Anatomy and development of the larval nervous system in Echinococcus multilocularis
JF - Frontiers in Zoology
N2 - Background
The metacestode larva of Echinococcus multilocularis (Cestoda: Taeniidae) develops in the liver of intermediate hosts (typically rodents, or accidentally in humans) as a labyrinth of interconnected cysts that infiltrate the host tissue, causing the disease alveolar echinococcosis. Within the cysts, protoscoleces (the infective stage for the definitive canid host) arise by asexual multiplication. These consist of a scolex similar to that of the adult, invaginated within a small posterior body. Despite the importance of alveolar echinococcosis for human health, relatively little is known about the basic biology, anatomy and development of E. multilocularis larvae, particularly with regard to their nervous system.
Results
We describe the existence of a subtegumental nerve net in the metacestode cysts, which is immunoreactive for acetylated tubulin-α and contains small populations of nerve cells that are labeled by antibodies raised against several invertebrate neuropeptides. However, no evidence was found for the existence of cholinergic or serotoninergic elements in the cyst wall. Muscle fibers occur without any specific arrangement in the subtegumental layer, and accumulate during the invaginations of the cyst wall that form brood capsules, where protoscoleces develop. The nervous system of the protoscolex develops independently of that of the metacestode cyst, with an antero-posterior developmental gradient. The combination of antibodies against several nervous system markers resulted in a detailed description of the protoscolex nervous system, which is remarkably complex and already similar to that of the adult worm.
Conclusions
We provide evidence for the first time of the existence of a nervous system in the metacestode cyst wall, which is remarkable given the lack of motility of this larval stage, and the lack of serotoninergic and cholinergic elements. We propose that it could function as a neuroendocrine system, derived from the nervous system present in the bladder tissue of other taeniids. The detailed description of the development and anatomy of the protoscolex neuromuscular system is a necessary first step toward the understanding of the developmental mechanisms operating in these peculiar larval stages.
KW - Echinococcus
KW - Metacestode
KW - Protoscolex
KW - Nervous system
KW - Neuropeptide
KW - Serotonin
KW - Acetylated tubulin
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96504
UR - http://www.frontiersinzoology.com/content/10/1/24
ER -
TY - JOUR
A1 - Zirkel, J.
A1 - Cecil, A.
A1 - Schäfer, F.
A1 - Rahlfs, S.
A1 - Ouedraogo, A.
A1 - Xiao, K.
A1 - Sawadogo, S.
A1 - Coulibaly, B.
A1 - Becker, K.
A1 - Dandekar, T.
T1 - Analyzing Thiol-Dependent Redox Networks in the Presence of Methylene Blue and Other Antimalarial Agents with RT-PCR-Supported in silico Modeling
JF - Bioinformatics and Biology Insights
N2 - BACKGROUND: In the face of growing resistance in malaria parasites to drugs, pharmacological combination therapies are important. There is accumulating evidence that methylene blue (MB) is an effective drug against malaria. Here we explore the biological effects of both MB alone and in combination therapy using modeling and experimental data.
RESULTS: We built a model of the central metabolic pathways in P. falciparum. Metabolic flux modes and their changes under MB were calculated by integrating experimental data (RT-PCR data on mRNAs for redox enzymes) as constraints and results from the YANA software package for metabolic pathway calculations. Several different lines of MB attack on Plasmodium redox defense were identified by analysis of the network effects. Next, chloroquine resistance based on pfmdr/and pfcrt transporters, as well as pyrimethamine/sulfadoxine resistance (by mutations in DHF/DHPS), were modeled in silico. Further modeling shows that MB has a favorable synergism on antimalarial network effects with these commonly used antimalarial drugs.
CONCLUSIONS: Theoretical and experimental results support that methylene blue should, because of its resistance-breaking potential, be further tested as a key component in drug combination therapy efforts in holoendemic areas.
KW - methylene blue
KW - malaria
KW - elementary mode analysis
KW - drug
KW - resistance
KW - combination therapy
KW - pathway
KW - metabolic flux
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123751
N1 - This is an open access article. Unrestricted non-commercial use is permitted provided the original work is properly cited.
VL - 6
ER -
TY - JOUR
A1 - Liu, Ruiqi
A1 - Kinoshita, Masato
A1 - Adolfi, Mateus C.
A1 - Schartl, Manfred
T1 - Analysis of the role of the Mc4r system in development, growth, and puberty of medaka
JF - Frontiers in Endocrinology
N2 - In mammals the melanocortin 4 receptor (Mc4r) signaling system has been mainly associated with the regulation of appetite and energy homeostasis. In fish of the genus Xiphophorus (platyfish and swordtails) puberty onset is genetically determined by a single locus, which encodes the mc4r. Wild populations of Xiphophorus are polymorphic for early and late-maturing individuals. Copy number variation of different mc4r alleles is responsible for the difference in puberty onset. To answer whether this is a special adaptation of the Mc4r signaling system in the lineage of Xiphophorus or a more widely conserved mechanism in teleosts, we studied the role of Mc4r in reproductive biology of medaka (Oryzias latipes), a close relative to Xiphophorus and a well-established model to study gonadal development. To understand the potential role of Mc4r in medaka, we characterized the major features of the Mc4r signaling system (mc4r, mrap2, pomc, agrp1). In medaka, all these genes are expressed before hatching. In adults, they are mainly expressed in the brain. The transcript of the receptor accessory protein mrap2 co-localizes with mc4r in the hypothalamus in adult brains indicating a conserved function of modulating Mc4r signaling. Comparing growth and puberty between wild-type and mc4r knockout medaka revealed that absence of Mc4r does not change puberty timing but significantly delays hatching. Embryonic development of knockout animals is retarded compared to wild-types. In conclusion, the Mc4r system in medaka is involved in regulation of growth rather than puberty.
KW - medaka
KW - Mc4r
KW - knockout
KW - puberty
KW - growth
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201472
VL - 10
ER -
TY - JOUR
A1 - Groh, Claudia
A1 - Rössler, Wolfgang
T1 - Analysis of Synaptic Microcircuits in the Mushroom Bodies of the Honeybee
JF - Insects
N2 - Mushroom bodies (MBs) are multisensory integration centers in the insect brain involved in learning and memory formation. In the honeybee, the main sensory input region (calyx) of MBs is comparatively large and receives input from mainly olfactory and visual senses, but also from gustatory/tactile modalities. Behavioral plasticity following differential brood care, changes in sensory exposure or the formation of associative long-term memory (LTM) was shown to be associated with structural plasticity in synaptic microcircuits (microglomeruli) within olfactory and visual compartments of the MB calyx. In the same line, physiological studies have demonstrated that MB-calyx microcircuits change response properties after associative learning. The aim of this review is to provide an update and synthesis of recent research on the plasticity of microcircuits in the MB calyx of the honeybee, specifically looking at the synaptic connectivity between sensory projection neurons (PNs) and MB intrinsic neurons (Kenyon cells). We focus on the honeybee as a favorable experimental insect for studying neuronal mechanisms underlying complex social behavior, but also compare it with other insect species for certain aspects. This review concludes by highlighting open questions and promising routes for future research aimed at understanding the causal relationships between neuronal and behavioral plasticity in this charismatic social insect.
KW - mushroom body
KW - microglomeruli
KW - projection neurons
KW - Kenyon cells
KW - dendritic specializations
KW - structural synaptic plasticity
KW - behavioral plasticity
KW - vision
KW - olfaction
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200774
SN - 2075-4450
VL - 11
IS - 1
ER -
TY - JOUR
A1 - Alsheimer, Manfred
A1 - Link, Jana
A1 - Leubner, Monika
A1 - Schmitt, Johannes
A1 - Göb, Eva
A1 - Benavente, Ricardo
A1 - Jeang, Kuan-Teh
A1 - Xu, Rener
T1 - Analysis of Meiosis in SUN1 Deficient Mice Reveals a Distinct Role of SUN2 in Mammalian Meiotic LINC Complex Formation and Function
N2 - LINC complexes are evolutionarily conserved nuclear envelope bridges, composed of SUN (Sad-1/UNC-84) and KASH (Klarsicht/ANC-1/Syne/homology) domain proteins. They are crucial for nuclear positioning and nuclear shape determination, and also mediate nuclear envelope (NE) attachment of meiotic telomeres, essential for driving homolog synapsis and recombination. In mice, SUN1 and SUN2 are the only SUN domain proteins expressed during meiosis, sharing their localization with meiosis-specific KASH5. Recent studies have shown that loss of SUN1 severely interferes with meiotic processes. Absence of SUN1 provokes defective telomere attachment and causes infertility. Here, we report that meiotic telomere attachment is not entirely lost in mice deficient for SUN1, but numerous telomeres are still attached to the NE through SUN2/KASH5-LINC complexes. In Sun12/2 meiocytes attached telomeres retained the capacity to form bouquetlike clusters. Furthermore, we could detect significant numbers of late meiotic recombination events in Sun12/2 mice. Together, this indicates that even in the absence of SUN1 telomere attachment and their movement within the nuclear envelope per se can be functional.
Author summary:
Correct genome haploidization during meiosis requires tightly regulated chromosome movements that follow a highly conserved choreography during prophase I. Errors in these movements cause subsequent meiotic defects, which typically lead to infertility. At the beginning of meiotic prophase, chromosome ends are tethered to the nuclear envelope (NE). This attachment of telomeres appears to be mediated by well-conserved membrane spanning protein complexes within the NE (LINC complexes). In mouse meiosis, the two main LINC components SUN1 and SUN2 were independently described to localize at the sites of telomere attachment. While SUN1 has been demonstrated to be critical for meiotic telomere attachment, the precise role of SUN2 in this context, however, has been discussed controversially in the field. Our current study was targeted to determine the factual capacity of SUN2 in telomere attachment and chromosome movements in SUN1 deficient mice. Remarkably, although telomere attachment is impaired in the absence of SUN1, we could find a yet undescribed SUN1-independent telomere attachment, which presumably is mediated by SUN2 and KASH5. This SUN2 mediated telomere attachment is stable throughout prophase I and functional in moving telomeres within the NE. Thus, our results clearly indicate that SUN1 and SUN2, at least partially, fulfill redundant meiotic functions.
KW - telomeres
KW - spermatocytes
KW - Oocytes
KW - meiosis
KW - protein domains
KW - cytoskeleton
KW - synapsis
KW - homologous chromosomes
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111355
ER -
TY - JOUR
A1 - Winkler, Christoph
A1 - Hong, Yunhan
A1 - Wittbrodt, Joachim
A1 - Schartl, Manfred
T1 - Analysis of heterologous and homologous promoters and enhancers in vitro and in vivo by gene transfer into Japanese medaka (Oryzias latipes) and Xiphophorus
N2 - Efficient expression systems are required for analysis of gene regulation and function in teleost fish. To develop such systems, a nurober of inducible or constitutive promoter and enhancer sequences of fish or higher vertebrate origin were tested for activity in a variety of fish celllines andin embryos of the Japanese medaka fish (Oryzias latipes) and Xiphophorus. The activity of the different promoterenhancer combinations were quantitated. Considerable differences were found for some constructs if tested in vitro or in vivo. From the data obtained, a set of expression vectors for basic research as weH as for aquaculture purposes were established.
KW - Schwertkärpfling
KW - Japankärpfling
KW - Gentransfer
KW - Enhancer
KW - Promotor
KW - In vitro
KW - In vivo
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86796
ER -
TY - JOUR
A1 - Maierhofer, Anna
A1 - Flunkert, Julia
A1 - Dittrich, Marcus
A1 - Müller, Tobias
A1 - Schindler, Detlev
A1 - Nanda, Indrajit
A1 - Haaf, Thomas
T1 - Analysis of global DNA methylation changes in primary human fibroblasts in the early phase following X-ray irradiation
JF - PLoS ONE
N2 - Epigenetic alterations may contribute to the generation of cancer cells in a multi-step process of tumorigenesis following irradiation of normal body cells. Primary human fibroblasts with intact cell cycle checkpoints were used as a model to test whether X-ray irradiation with 2 and 4 Gray induces direct epigenetic effects (within the first cell cycle) in the exposed cells. ELISA-based fluorometric assays were consistent with slightly reduced global DNA methylation and hydroxymethylation, however the observed between-group differences were usually not significant. Similarly, bisulfite pyrosequencing of interspersed LINE-1 repeats and centromeric α-satellite DNA did not detect significant methylation differences between irradiated and non-irradiated cultures. Methylation of interspersed ALU repeats appeared to be slightly increased (one percentage point; p = 0.01) at 6 h after irradiation with 4 Gy. Single-cell analysis showed comparable variations in repeat methylation among individual cells in both irradiated and control cultures. Radiation-induced changes in global repeat methylation, if any, were much smaller than methylation variation between different fibroblast strains. Interestingly, α-satellite DNA methylation positively correlated with gestational age. Finally, 450K methylation arrays mainly targeting genes and CpG islands were used for global DNA methylation analysis. There were no detectable methylation differences in genic (promoter, 5' UTR, first exon, gene body, 3' UTR) and intergenic regions between irradiated and control fibroblast cultures. Although we cannot exclude minor effects, i.e. on individual CpG sites, collectively our data suggest that global DNA methylation remains rather stable in irradiated normal body cells in the early phase of DNA damage response.
KW - DNA methylation
KW - fibroblasts
KW - methylation
KW - alu elements
KW - DNA damage
KW - epigenetics
KW - cancer treatment
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170895
VL - 12
IS - 5
ER -
TY - JOUR
A1 - Förnzler, Dorothee
A1 - Wittbrodt, Joachim
A1 - Schartl, M.anfred
T1 - Analysis of an esterase linked to a locus involved in the regulation of the melanoma oncogene and isolation of polymorphic marker sequences in Xiphophorus
N2 - Melanoma formation in Xiphophorus hybrids is mediated by a growth factor receptor tyrosine kinase oncogene encoded by the Tu locus. In the wild-type parental fish no tumors occur due to the activity of a locus that regulates the activity of the melanoma oncogene. Molecu/ar identification of this regulatory locus (R) requires a precise physical map of the chromosomal region. Therefore we studied esterase isozymes in Xiphophorus, two of which have been previously reported to be linked to locus R. We confinn that ES 1 is a distant marker for R ( approx. 30cM), and contrary to earlier studies, we show that this isozyme is present in all species of the genus and at similar activity Ievels in all organs tested. ES4, which has also been reported to be linked to R, was found to be a misclassification of liver ES1. In an attempt to identify markersthat bridge the large distance between ESl and R, we have generated DNA probes which are highly polymorphic. They will be useful in finding Iandmarks on a physical map of the R-containing chromosomal region.
KW - Physiologische Chemie
KW - Xiphophorus
KW - melanoma ; oncogene regulation ; esterase ; molecular marker sequences
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61726
ER -
TY - JOUR
A1 - Chipperfield, Joseph D.
A1 - Dytham, Calvin
A1 - Hovestadt, Thomas
T1 - An Updated Algorithm for the Generation of Neutral Landscapes by Spectral Synthesis
N2 - Background: Patterns that arise from an ecological process can be driven as much from the landscape over which the process is run as it is by some intrinsic properties of the process itself. The disentanglement of these effects is aided if it possible to run models of the process over artificial landscapes with controllable spatial properties. A number of different methods for the generation of so-called ‘neutral landscapes’ have been developed to provide just such a tool. Of these methods, a particular class that simulate fractional Brownian motion have shown particular promise. The existing methods of simulating fractional Brownian motion suffer from a number of problems however: they are often not easily generalisable to an arbitrary number of dimensions and produce outputs that can exhibit some undesirable artefacts. Methodology: We describe here an updated algorithm for the generation of neutral landscapes by fractional Brownian motion that do not display such undesirable properties. Using Monte Carlo simulation we assess the anisotropic properties of landscapes generated using the new algorithm described in this paper and compare it against a popular benchmark algorithm. Conclusion/Significance: The results show that the existing algorithm creates landscapes with values strongly correlated in the diagonal direction and that the new algorithm presented here corrects this artefact. A number of extensions of the algorithm described here are also highlighted: we describe how the algorithm can be employed to generate landscapes that display different properties in different dimensions and how they can be combined with an environmental gradient to produce landscapes that combine environmental variation at the local and macro scales.
KW - Landschaft
KW - Monte-Carlo-Simulation
KW - Brownsche Bewegung
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68938
ER -
TY - JOUR
A1 - Higgins, M. J.
A1 - Smilinich, N. J.
A1 - Sait, S.
A1 - Koenig, A.
A1 - Pongratz, J.
A1 - Gessler, Manfred
A1 - Richard III., C. W.
A1 - James, M. R.
A1 - Sanford, J. P.
A1 - Kim, B.-W.
A1 - Cattelane, J.
A1 - Nowak, N. J.
A1 - Winterpacht, A.
A1 - Zabel, B. U.
A1 - Munroe, D. J.
A1 - Bric, E.
A1 - Housman, D. E.
A1 - Jones, C.
A1 - Nakamura, Y.
A1 - Gerhard, D. S.
A1 - Shows, T. B.
T1 - An Ordered NotI Fragment Map of Human Chromosome Band 11p15
N2 - An ordered NotI fragment map containing over 60 loci and encompassing approximately 17 Mb has been constructed for human chromosome band llpl5. Forty-two probes, including 11 NotI-linking cosmids, were subregionaUy mapped to llpl5 using a subset of the Jl-deletion hybrids. These and 23 other probes defining loci previously mapped to 11p15 were hybridized to genomic DNA digested with NotI and 5 other infrequently cleaving restriction enzymes and separated by pulsed-field gel electrophoresis. Thirty-nine distinct NotI fragments were detected encompassing approximately 85% of the estimated length of llp15. The predicted order of the gene loci used is cenMYODI- PTH-CALCA-ST5-RBTNI-HPX-HBB-RRMlTH/ INS!1GF2-H19-CTSD-MUC2-DRD4-HRAS-RNHtel. This map wiu allow higher resolution mapping of new Ilp15 markers, facilitate positional cloning of disease genes, and provide a framework for the physical mapping of llp15 in clone contigs.
KW - Genom / Genkartierung / Genanalyse
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45766
ER -
TY - JOUR
A1 - Li, Kunkun
A1 - Prada, Juan
A1 - Damineli, Daniel S. C.
A1 - Liese, Anja
A1 - Romeis, Tina
A1 - Dandekar, Thomas
A1 - Feijó, José A.
A1 - Hedrich, Rainer
A1 - Konrad, Kai Robert
T1 - An optimized genetically encoded dual reporter for simultaneous ratio imaging of Ca\(^{2+}\) and H\(^{+}\) reveals new insights into ion signaling in plants
JF - New Phytologist
N2 - Whereas the role of calcium ions (Ca\(^{2+}\)) in plant signaling is well studied, the physiological significance of pH‐changes remains largely undefined.
Here we developed CapHensor, an optimized dual‐reporter for simultaneous Ca\(^{2+}\) and pH ratio‐imaging and studied signaling events in pollen tubes (PTs), guard cells (GCs), and mesophyll cells (MCs). Monitoring spatio‐temporal relationships between membrane voltage, Ca\(^{2+}\)‐ and pH‐dynamics revealed interconnections previously not described.
In tobacco PTs, we demonstrated Ca\(^{2+}\)‐dynamics lag behind pH‐dynamics during oscillatory growth, and pH correlates more with growth than Ca\(^{2+}\). In GCs, we demonstrated abscisic acid (ABA) to initiate stomatal closure via rapid cytosolic alkalization followed by Ca2+ elevation. Preventing the alkalization blocked GC ABA‐responses and even opened stomata in the presence of ABA, disclosing an important pH‐dependent GC signaling node. In MCs, a flg22‐induced membrane depolarization preceded Ca2+‐increases and cytosolic acidification by c. 2 min, suggesting a Ca\(^{2+}\)/pH‐independent early pathogen signaling step. Imaging Ca2+ and pH resolved similar cytosol and nuclear signals and demonstrated flg22, but not ABA and hydrogen peroxide to initiate rapid membrane voltage‐, Ca\(^{2+}\)‐ and pH‐responses.
We propose close interrelation in Ca\(^{2+}\)‐ and pH‐signaling that is cell type‐ and stimulus‐specific and the pH having crucial roles in regulating PT growth and stomata movement.
KW - abscisic acid (ABA)
KW - calcium
KW - flg22
KW - guard cells
KW - imaging
KW - ion signaling
KW - pH
KW - pollen tube
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239847
VL - 230
IS - 6
SP - 2292
EP - 2310
ER -
TY - JOUR
A1 - Hornick, Thomas
A1 - Richter, Anett
A1 - Harpole, William Stanley
A1 - Bastl, Maximilian
A1 - Bohlmann, Stephanie
A1 - Bonn, Aletta
A1 - Bumberger, Jan
A1 - Dietrich, Peter
A1 - Gemeinholzer, Birgit
A1 - Grote, Rüdiger
A1 - Heinold, Bernd
A1 - Keller, Alexander
A1 - Luttkus, Marie L.
A1 - Mäder, Patrick
A1 - Motivans Švara, Elena
A1 - Passonneau, Sarah
A1 - Punyasena, Surangi W.
A1 - Rakosy, Demetra
A1 - Richter, Ronny
A1 - Sickel, Wiebke
A1 - Steffan‐Dewenter, Ingolf
A1 - Theodorou, Panagiotis
A1 - Treudler, Regina
A1 - Werchan, Barbora
A1 - Werchan, Matthias
A1 - Wolke, Ralf
A1 - Dunker, Susanne
T1 - An integrative environmental pollen diversity assessment and its importance for the Sustainable Development Goals
JF - Plants, People, Planet
N2 - Societal Impact Statement
Pollen relates to many aspects of human and environmental health, which protection and improvement are endorsed by the United Nations Sustainable Development Goals. By highlighting these connections in the frame of current challenges in monitoring and research, we discuss the need of more integrative and multidisciplinary pollen research related to societal needs, improving health of humans and our ecosystems for a sustainable future.
Summary
Pollen is at once intimately part of the reproductive cycle of seed plants and simultaneously highly relevant for the environment (pollinators, vector for nutrients, or organisms), people (food safety and health), and climate (cloud condensation nuclei and climate reconstruction). We provide an interdisciplinary perspective on the many and connected roles of pollen to foster a better integration of the currently disparate fields of pollen research, which would benefit from the sharing of general knowledge, technical advancements, or data processing solutions. We propose a more interdisciplinary and holistic research approach that encompasses total environmental pollen diversity (ePD) (wind and animal and occasionally water distributed pollen) at multiple levels of diversity (genotypic, phenotypic, physiological, chemical, and functional) across space and time. This interdisciplinary approach holds the potential to contribute to pressing human issues, including addressing United Nations Sustainable Development Goals, fostering social and political awareness of these tiny yet important and fascinating particles.
KW - aerobiology
KW - allergy
KW - diversity
KW - environmental monitoring
KW - food safety
KW - paleoecology
KW - palynology
KW - pollination
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-276487
VL - 4
IS - 2
SP - 110
EP - 121
ER -
TY - JOUR
A1 - Alnusaire, Taghreed S.
A1 - Sayed, Ahmed M.
A1 - Elmaidomy, Abeer H.
A1 - Al-Sanea, Mohammad M.
A1 - Albogami, Sarah
A1 - Albqmi, Mha
A1 - Alowaiesh, Bassam F.
A1 - Mostafa, Ehab M.
A1 - Musa, Arafa
A1 - Youssif, Khayrya A.
A1 - Refaat, Hesham
A1 - Othman, Eman M.
A1 - Dandekar, Thomas
A1 - Alaaeldin, Eman
A1 - Ghoneim, Mohammed M.
A1 - Abdelmohsen, Usama Ramadan
T1 - An in vitro and in silico study of the enhanced antiproliferative and pro-oxidant potential of Olea europaea L. cv. Arbosana leaf extract via elastic nanovesicles (spanlastics)
JF - Antioxidants
N2 - The olive tree is a venerable Mediterranean plant and often used in traditional medicine. The main aim of the present study was to evaluate the effect of Olea europaea L. cv. Arbosana leaf extract (OLE) and its encapsulation within a spanlastic dosage form on the improvement of its pro-oxidant and antiproliferative activity against HepG-2, MCF-7, and Caco-2 human cancer cell lines. The LC-HRESIMS-assisted metabolomic profile of OLE putatively annotated 20 major metabolites and showed considerable in vitro antiproliferative activity against HepG-2, MCF-7, and Caco-2 cell lines with IC\(_{50}\) values of 9.2 ± 0.8, 7.1 ± 0.9, and 6.5 ± 0.7 µg/mL, respectively. The encapsulation of OLE within a (spanlastic) nanocarrier system, using a spraying method and Span 40 and Tween 80 (4:1 molar ratio), was successfully carried out (size 41 ± 2.4 nm, zeta potential 13.6 ± 2.5, and EE 61.43 ± 2.03%). OLE showed enhanced thermal stability, and an improved in vitro antiproliferative effect against HepG-2, MCF-7, and Caco-2 (IC\(_{50}\) 3.6 ± 0.2, 2.3 ± 0.1, and 1.8 ± 0.1 µg/mL, respectively) in comparison to the unprocessed extract. Both preparations were found to exhibit pro-oxidant potential inside the cancer cells, through the potential inhibitory activity of OLE against glutathione reductase and superoxide dismutase (IC\(_{50}\) 1.18 ± 0.12 and 2.33 ± 0.19 µg/mL, respectively). These inhibitory activities were proposed via a comprehensive in silico study to be linked to the presence of certain compounds in OLE. Consequently, we assume that formulating such a herbal extract within a suitable nanocarrier would be a promising improvement of its therapeutic potential.
KW - olive
KW - metabolomic profiling
KW - antiproliferative
KW - pro-oxidant
KW - encapsulation
KW - spanlastic
KW - nanocarrier
KW - docking
KW - molecular dynamics simulation
KW - Olea
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250064
SN - 2076-3921
VL - 10
IS - 12
ER -
TY - JOUR
A1 - Osman, Mohamed
A1 - Stigloher, Christian
A1 - Mueller, Martin J.
A1 - Waller, Frank
T1 - An improved growth medium for enhanced inoculum production of the plant growth-promoting fungus Serendipita indica
JF - Plant Methods
N2 - Background
The plant endophytic fungus Serendipita indica colonizes roots of a wide range of plant species and can enhance growth and stress resistance of these plants. Due to its ease of axenic cultivation and its broad host plant range including the model plant Arabidopsis thaliana and numerous crop plants, it is widely used as a model fungus to study beneficial fungus-root interactions. In addition, it was suggested to be utilized for commercial applications, e.g. to enhance yield in barley and other species. To produce inoculum, S. indica is mostly cultivated in a complex Hill-Kafer medium (CM medium), however, growth in this medium is slow, and yield of chlamydospores, which are often used for plant root inoculation, is relatively low.
Results
We tested and optimized a simple vegetable juice-based medium for an enhanced yield of fungal inoculum. The described vegetable juice (VJ) medium is based on commercially available vegetable juice and is easy to prepare. VJ medium was superior to the currently used CM medium with respect to biomass production in liquid medium and hyphal growth on agar plates. Using solid VJ medium supplemented with sucrose (VJS), a high amount of chlamydospores developed already after 8 days of cultivation, producing significantly more spores than on CM medium. Use of VJ medium is not restricted to S. indica, as it also supported growth of two pathogenic fungi often used in plant pathology experiments: the ascomycete Fusarium graminearum, the causal agent of Fusarium head blight disease on wheat and barley, and Verticillium longisporum, the causal agent of verticillium wilt.
Conclusions
The described VJ medium is recommended for streamlined and efficient production of inoculum for the plant endophytic fungus Serendipita indica and might prove superior for the propagation of other fungi for research purposes.
KW - Serendipita indica
KW - Plant root endophyte
KW - Inoculum production
KW - Complex medium
KW - Aspergillus medium
KW - Vegetable juice
KW - Plant growth promotion
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229186
VL - 16
ER -
TY - JOUR
A1 - Hovestadt, Thomas
A1 - Mitesser, Oliver
A1 - Elmes, Graham
A1 - Thomas, Jeremy A.
A1 - Hochberg, Michael E.
T1 - An Evolutionarily Stable Strategy model for the evolution of dimorphic development in the butterfly Maculinea rebeli, a social parasite of Myrmica Ant Colonies
N2 - Caterpillars of the butterfly Maculinea rebeli develop as parasites inside ant colonies. In intensively studied French populations, about 25% of caterpillars mature within 1 year (fast-developing larvae [FDL]) and the others after 2 years (slow-developing larvae [SDL]); all available evidence indicates that this ratio is under the control of egg-laying females. We present an analytical model to predict the evolutionarily stable fraction of FDL (pESS). The model accounts for added winter mortality of SDL, general and kin competition among caterpillars, a competitive advantage of SDL over newly entering FDL (priority effect), and the avoidance of renewed infection of ant nests by butterflies in the coming season (segregation). We come to the following conclusions: (1) all factors listed above can promote the evolution of delayed development; (2) kin competition and segregation stabilize pESS near 0.5; and (3) a priority effect is the only mechanism potentially selecting for. However, given the empirical data, pESS is predicted to fall closer to 0.5 than to the 0.25 that has been observed. In this particular system, bet hedging cannot explain why more than 50% of larvae postpone growth. Presumably, other fitness benefits for SDL, for example, higher fertility or longevity, also contribute to the evolution of delayed development. The model presented here may be of general applicability for systems where maturing individuals compete in small subgroups.
KW - delayed development
KW - growth dimorphism
KW - evolutionarily stable strategy (ESS)
KW - ant-butterfly interaction
KW - social parasitism
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48165
ER -
TY - JOUR
A1 - Breitenbach, Tim
A1 - Helfrich-Förster, Charlotte
A1 - Dandekar, Thomas
T1 - An effective model of endogenous clocks and external stimuli determining circadian rhythms
JF - Scientific Reports
N2 - Circadian endogenous clocks of eukaryotic organisms are an established and rapidly developing research field. To investigate and simulate in an effective model the effect of external stimuli on such clocks and their components we developed a software framework for download and simulation. The application is useful to understand the different involved effects in a mathematical simple and effective model. This concerns the effects of Zeitgebers, feedback loops and further modifying components. We start from a known mathematical oscillator model, which is based on experimental molecular findings. This is extended with an effective framework that includes the impact of external stimuli on the circadian oscillations including high dose pharmacological treatment. In particular, the external stimuli framework defines a systematic procedure by input-output-interfaces to couple different oscillators. The framework is validated by providing phase response curves and ranges of entrainment. Furthermore, Aschoffs rule is computationally investigated. It is shown how the external stimuli framework can be used to study biological effects like points of singularity or oscillators integrating different signals at once. The mathematical framework and formalism is generic and allows to study in general the effect of external stimuli on oscillators and other biological processes. For an easy replication of each numerical experiment presented in this work and an easy implementation of the framework the corresponding Mathematica files are fully made available. They can be downloaded at the following link: https://www.biozentrum.uni-wuerzburg.de/bioinfo/computing/circadian/.
KW - computational biology and bioinformatics
KW - systems biology
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-261655
VL - 11
IS - 1
ER -
TY - JOUR
A1 - Senecal, Jean-Luc
A1 - Isabelle, Catherine
A1 - Fritzler, Marvin J.
A1 - Targoff, Ira N.
A1 - Goldstein, Rose
A1 - Gagne, Michel
A1 - Raynauld, Jean-Pierre
A1 - Joyal, France
A1 - Troyanov, Yves
A1 - Dabauvalle, Marie-Christine
T1 - An Autoimmune Myositis-Overlap Syndrome Associated With Autoantibodies to Nuclear Pore Complexes Description and Long-Term Follow-up of the Anti-Nup Syndrome
JF - Medicine
N2 - Autoimmune myositis encompasses various myositis-overlap syndromes, each being identified by the presence of serum marker autoantibodies. We describe a novel myositis-overlap syndrome in 4 patients characterized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes. The clinical phenotype was characterized by prominent myositis in association with erosive, anti-CCP, and rheumatoid factor-positive arthritis, trigeminal neuralgia, mild interstitial lung disease, Raynaud phenomenon, and weight loss. The myositis was typically chronic, relapsing, and refractory to corticosteroids alone, but remitted with the addition of a second immuno-modulating drug. There was no clinical or laboratory evidence for liver disease. The prognosis was good with 100% long-term survival (mean follow-up 19.5 yr). By indirect immunofluorescence on HEp-2 cells, sera from all 4 patients displayed a high titer of antinuclear autoantibodies (ANA) with a distinct punctate peripheral (rim) fluorescent pattern of the nuclear envelope characteristic of nuclear pore complexes. Reactivity with nuclear pore complexes was confirmed by immunoelectron microscopy. In a cohort of 100 French Canadian patients with autoimmune myositis, the nuclear pore complex fluorescent ANA pattern was restricted to these 4 patients (4%). It was not observed in sera from 393 adult patients with systemic sclerosis (n = 112), mixed connective tissue disease (n = 35), systemic lupus (n = 94), rheumatoid arthritis (n = 45), or other rheumatic diseases (n = 107), nor was it observed in 62 normal adults. Autoantibodies to nuclear pore complexes were predominantly of IgG isotype. No other IgG autoantibody markers for defined connective tissue diseases or overlap syndromes were present, indicating a selective and highly focused immune response. In 3 patients, anti-nuclear pore complex autoantibody titers varied in parallel with myositis activity, suggesting a pathogenic link to pathophysiology. The nuclear pore complex proteins, that is, nucleoporins (nup), recognized by these sera were heterogeneous and included Nup358/RanBP2 (n = 2 patients), Nup90 (n = 1), Nup62 (n = 1), and gp210 (n = 1). Taken together the data suggest that nup autoantigens themselves drive the anti-nup autoimmune response. Immunogenetically, the 4 patients shared the DQA1*0501 allele associated with an increased risk for autoimmune myositis. In conclusion, we report an apparent novel subset of autoimmune myositis in our population of French Canadian patients with connective tissue diseases. This syndrome is recognized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes that react with nups, consistent with an "anti-nupsyndrome.''
KW - idiopathic inflammatory myopathies
KW - primary biliary-cirrhosis
KW - transfer RNA-synthetases
KW - major histocompatibility complex
KW - systemic sclerosis
KW - French-Canadian patients
KW - protein
KW - predictive factors
KW - envelope
KW - antibodies
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114829
SN - 0025-7974
VL - 93
IS - 24
ER -
TY - JOUR
A1 - Hoppe, J.
A1 - Sebald, Walter
T1 - Amino acid sequence of the proteolipid subunit of the proton-translocating ATPase complex from the thermophilic bacterium PS-3
N2 - No abstract available
KW - Biochemie
Y1 - 1980
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62754
ER -
TY - JOUR
A1 - Velours, J.
A1 - Esparza, M.
A1 - Hoppe, J.
A1 - Sebald, Walter
A1 - Guerin, B.
T1 - Amino acid sequence of a new mitochondrially synthesized proteolipid of the ATP synthase of Saccharomyces cerevisiae
N2 - The purification and the amino acid sequence of a proteolipid translated on ribosomes in yeast mitochondria is reported. This protein, which is a subunit of the A TP synthase, was purified by extraction with chloroform/methanol (2/1) and subsequent chromatography on phosphocellulose and reverse phase h.p.l.c. A mol. wt. of 5500 was estimated by chromatography on Bio-Gel P-30 in 8011/o fonnie acid. The complete amino acid sequence of this protein was determined by automated solid phase Edman degradation of the whole protein and of fragments obtained after cleavage with cyanogen bromide. The sequence analysis indicates a length of 48 amino acid residues. The calculated mol. wt. of 5870 corresponds to the value found by gel chromatography. This polypeptide contains three basic residues and no negatively charged side chain. The three basic residues are clustered at the C terminus. The primary structure of this protein is in full agreement with the predicted amino acid sequence of the putative polypeptide encoded by the mitochondrial aap1 gene recently discovered in Saccharomyces cerevisiae. Moreover, this protein shows 5011/o homology with the amino acid sequence of a putative polypeptide encoded by an unidentified reading frame also discovered near the mitochondrial ATPase subunit 6 genein Aspergillus nidulans.
KW - Biochemie
KW - ATP synthase
KW - mitochondrially translated
KW - proteolipid
KW - sequence subunit
Y1 - 1984
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62695
ER -
TY - JOUR
A1 - Dandekar, Thomas
A1 - Argos, Patrick
T1 - Amiloride-sensitive epithelial Na\(^+\) channel is made of three homologous subunits
N2 - No abstract available
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29734
ER -
TY - JOUR
A1 - Schwarz, Roland F.
A1 - Tamuri, Asif U.
A1 - Kultys, Marek
A1 - King, James
A1 - Godwin, James
A1 - Florescu, Ana M.
A1 - Schultz, Jörg
A1 - Goldman, Nick
T1 - ALVIS: interactive non-aggregative visualization and explorative analysis of multiple sequence alignments
JF - Nucleic Acids Research
N2 - Sequence Logos and its variants are the most commonly used method for visualization of multiple sequence alignments (MSAs) and sequence motifs. They provide consensus-based summaries of the sequences in the alignment. Consequently, individual sequences cannot be identified in the visualization and covariant sites are not easily discernible. We recently proposed Sequence Bundles, a motif visualization technique that maintains a one-to-one relationship between sequences and their graphical representation and visualizes covariant sites. We here present Alvis, an open-source platform for the joint explorative analysis of MSAs and phylogenetic trees, employing Sequence Bundles as its main visualization method. Alvis combines the power of the visualization method with an interactive toolkit allowing detection of covariant sites, annotation of trees with synapomorphies and homoplasies, and motif detection. It also offers numerical analysis functionality, such as dimension reduction and classification. Alvis is user-friendly, highly customizable and can export results in publication-quality figures. It is available as a full-featured standalone version (http://www.bitbucket.org/rfs/alvis) and its Sequence Bundles visualization module is further available as a web application (http://science-practice.com/projects/sequence-bundles).
KW - visualization
KW - multiple sequence alignments
KW - phylogenetic trees
KW - Alvis
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166374
VL - 44
IS - 8
ER -
TY - JOUR
A1 - Gupta, Shishir K.
A1 - Srivastava, Mugdha
A1 - Minocha, Rashmi
A1 - Akash, Aman
A1 - Dangwal, Seema
A1 - Dandekar, Thomas
T1 - Alveolar regeneration in COVID-19 patients: a network perspective
JF - International Journal of Molecular Sciences
N2 - A viral infection involves entry and replication of viral nucleic acid in a host organism, subsequently leading to biochemical and structural alterations in the host cell. In the case of SARS-CoV-2 viral infection, over-activation of the host immune system may lead to lung damage. Albeit the regeneration and fibrotic repair processes being the two protective host responses, prolonged injury may lead to excessive fibrosis, a pathological state that can result in lung collapse. In this review, we discuss regeneration and fibrosis processes in response to SARS-CoV-2 and provide our viewpoint on the triggering of alveolar regeneration in coronavirus disease 2019 (COVID-19) patients.
KW - COVID-19
KW - SARS-CoV-2
KW - alveolar regeneration
KW - alveolar fibrosis
KW - signaling pathway
KW - network biology
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284307
SN - 1422-0067
VL - 22
IS - 20
ER -
TY - JOUR
A1 - Degen, Tobias
A1 - Hovestadt, Thomas
A1 - Mitesser, Oliver
A1 - Hölker, Franz
T1 - Altered sex-specific mortality and female mating success: ecological effects and evolutionary responses
JF - Ecosphere
N2 - Theory predicts that males and females should often join the mating pool at different times (sexual dimorphism in timing of emergence [SDT]) as the degree of SDT affects female mating success. We utilize an analytical model to explore (1) how important SDT is for female mating success, (2) how mating success might change if either sex's mortality (abruptly) increases, and (3) to what degree evolutionary responses in SDT may be able to mitigate the consequences of such mortality increase. Increasing male pre‐mating mortality has a non‐linear effect on the fraction of females mated: The effect is initially weak, but at some critical level a further increase in male mortality has a stronger effect than a similar increase in female mortality. Such a change is expected to impose selection for reduced SDT. Increasing mortality during the mating season has always a stronger effect on female mating success if the mortality affects the sex that emerges first. This bias results from the fact that enhancing mortality of the earlier emerging sex reduces female–male encounter rates. However, an evolutionary response in SDT may effectively mitigate such consequences. Further, if considered independently for females and males, the predicted evolutionary response in SDT could be quite dissimilar. The difference between female and male evolutionary response in SDT leads to marked differences in the fraction of fertilized females under certain conditions. Our model may provide general guidelines for improving harvesting of populations, conservation management of rare species under altered environmental conditions, or maintaining long‐term efficiency of pest‐control measures.
KW - evolutionary response
KW - sexual dimorphism in timing
KW - sex-specific mortality
KW - reproductive asynchrony
KW - mating success
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170953
VL - 8
IS - 5
ER -
TY - JOUR
A1 - Kerner, Janika M.
A1 - Krauss, Jochen
A1 - Maihoff, Fabienne
A1 - Bofinger, Lukas
A1 - Classen, Alice
T1 - Alpine butterflies want to fly high: Species and communities shift upwards faster than their host plants
JF - Ecology
N2 - Despite sometimes strong codependencies of insect herbivores and plants, the responses of individual taxa to accelerating climate change are typically studied in isolation. For this reason, biotic interactions that potentially limit species in tracking their preferred climatic niches are ignored. Here, we chose butterflies as a prominent representative of herbivorous insects to investigate the impacts of temperature changes and their larval host plant distributions along a 1.4‐km elevational gradient in the German Alps. Following a sampling protocol of 2009, we revisited 33 grassland plots in 2019 over an entire growing season. We quantified changes in butterfly abundance and richness by repeated transect walks on each plot and disentangled the direct and indirect effects of locally assessed temperature, site management, and larval and adult food resource availability on these patterns. Additionally, we determined elevational range shifts of butterflies and host plants at both the community and species level. Comparing the two sampled years (2009 and 2019), we found a severe decline in butterfly abundance and a clear upward shift of butterflies along the elevational gradient. We detected shifts in the peak of species richness, community composition, and at the species level, whereby mountainous species shifted particularly strongly. In contrast, host plants showed barely any change, neither in connection with species richness nor individual species shifts. Further, temperature and host plant richness were the main drivers of butterfly richness, with change in temperature best explaining the change in richness over time. We concluded that host plants were not yet hindering butterfly species and communities from shifting upwards. However, the mismatch between butterfly and host plant shifts might become a problem for this very close plant–herbivore relationship, especially toward higher elevations, if butterflies fail to adapt to new host plants. Further, our results support the value of conserving traditional extensive pasture use as a promoter of host plant and, hence, butterfly richness.
KW - Alps
KW - altitudinal gradient
KW - global warming
KW - grazing
KW - Lepidoptera
KW - mountain biodiversity
KW - plant–herbivore interactions
KW - species range shifts
KW - upslope shift
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312015
VL - 104
IS - 1
ER -
TY - JOUR
A1 - Rajab, Suhaila
A1 - Bismin, Leah
A1 - Schwarze, Simone
A1 - Pinggera, Alexandra
A1 - Greger, Ingo H.
A1 - Neuweiler, Hannes
T1 - Allosteric coupling of sub-millisecond clamshell motions in ionotropic glutamate receptor ligand-binding domains
JF - Communications Biology
N2 - Ionotropic glutamate receptors (iGluRs) mediate signal transmission in the brain and are important drug targets. Structural studies show snapshots of iGluRs, which provide a mechanistic understanding of gating, yet the rapid motions driving the receptor machinery are largely elusive. Here we detect kinetics of conformational change of isolated clamshell-shaped ligand-binding domains (LBDs) from the three major iGluR sub-types, which initiate gating upon binding of agonists. We design fluorescence probes to measure domain motions through nanosecond fluorescence correlation spectroscopy. We observe a broad kinetic spectrum of LBD dynamics that underlie activation of iGluRs. Microsecond clamshell motions slow upon dimerization and freeze upon binding of full and partial agonists. We uncover allosteric coupling within NMDA LBD hetero-dimers, where binding of L-glutamate to the GluN2A LBD stalls clamshell motions of the glycine-binding GluN1 LBD. Our results reveal rapid LBD dynamics across iGluRs and suggest a mechanism of negative allosteric cooperativity in NMDA receptors.
KW - fluorescence spectroscopy
KW - kinetics
KW - ligand-gated ion channels
KW - molecular neuroscience
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-261678
VL - 4
IS - 1
ER -
TY - JOUR
A1 - Matos, Isa
A1 - Machado, Miguel P.
A1 - Schartl, Manfred
A1 - Coelho, Maria Manuela
T1 - Allele-specific expression variation at different ploidy levels in Squalius alburnoides
JF - Scientific Reports
N2 - Allopolyploid plants are long known to be subject to a homoeolog expression bias of varying degree. The same phenomenon was only much later suspected to occur also in animals based on studies of single selected genes in an allopolyploid vertebrate, the Iberian fish Squalius alburnoides. Consequently, this species became a good model for understanding the evolution of gene expression regulation in polyploid vertebrates. Here, we analyzed for the first time genome-wide allele-specific expression data from diploid and triploid hybrids of S. alburnoides and compared homoeolog expression profiles of adult livers and of juveniles. Co-expression of alleles from both parental genomic types was observed for the majority of genes, but with marked homoeolog expression bias, suggesting homoeolog specific reshaping of expression level patterns in hybrids. Complete silencing of one allele was also observed irrespective of ploidy level, but not transcriptome wide as previously speculated. Instead, it was found only in a restricted number of genes, particularly ones with functions related to mitochondria and ribosomes. This leads us to hypothesize that allelic silencing may be a way to overcome intergenomic gene expression interaction conflicts, and that homoeolog expression bias may be an important mechanism in the achievement of sustainable genomic interactions, mandatory to the success of allopolyploid systems, as in S. alburnoides.
KW - Gene expression analysis
KW - Transcription
KW - Transcriptomic
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200910
VL - 9
ER -
TY - JOUR
A1 - Wegener, Christian
A1 - Chen, Jiangtian
T1 - Allatostatin A signalling: progress and new challenges from a paradigmatic pleiotropic invertebrate neuropeptide family
JF - Frontiers in Physiology
N2 - Neuropeptides have gained broad attraction in insect neuroscience and physiology, as new genetic tools are increasingly uncovering their wide-ranging pleiotropic functions with high cellular resolution. Allatostatin A (AstA) peptides constitute one of the best studied insect neuropeptide families. In insects and other panarthropods, AstA peptides qualify as brain-gut peptides and have regained attention with the discovery of their role in regulating feeding, growth, activity/sleep and learning. AstA receptor homologs are found throughout the protostomia and group with vertebrate somatostatin/galanin/kisspeptin receptors. In this review, we summarise the current knowledge on the evolution and the pleiotropic and cell-specific non-allatostatic functions of AstA. We speculate about the core functions of AstA signalling, and derive open questions and challengesfor future research on AstA and invertebrate neuropeptides in general.
KW - neuropeptide signalling
KW - feeding
KW - intestinal control
KW - sleep/activity
KW - kisspeptin/galanin/spexin signalling
KW - metabolism and growth
KW - learning
KW - cardioactive factor
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-278749
SN - 1664-042X
VL - 13
ER -
TY - JOUR
A1 - Chen, Jiangtian
A1 - Reiher, Wencke
A1 - Hermann-Luibl, Christiane
A1 - Sellami, Azza
A1 - Cognigni, Paola
A1 - Kondo, Shu
A1 - Helfrich-Förster, Charlotte
A1 - Veenstra, Jan A.
A1 - Wegener, Christian
T1 - Allatostatin A Signalling in Drosophila Regulates Feeding and Sleep and Is Modulated by PDF
JF - PLoS Genetics
N2 - Feeding and sleep are fundamental behaviours with significant interconnections and cross-modulations. The circadian system and peptidergic signals are important components of this modulation, but still little is known about the mechanisms and networks by which they interact to regulate feeding and sleep. We show that specific thermogenetic activation of peptidergic Allatostatin A (AstA)-expressing PLP neurons and enteroendocrine cells reduces feeding and promotes sleep in the fruit fly Drosophila. The effects of AstA cell activation are mediated by AstA peptides with receptors homolog to galanin receptors subserving similar and apparently conserved functions in vertebrates. We further identify the PLP neurons as a downstream target of the neuropeptide pigment-dispersing factor (PDF), an output factor of the circadian clock. PLP neurons are contacted by PDF-expressing clock neurons, and express a functional PDF receptor demonstrated by cAMP imaging. Silencing of AstA signalling and continuous input to AstA cells by tethered PDF changes the sleep/activity ratio in opposite directions but does not affect rhythmicity. Taken together, our results suggest that pleiotropic AstA signalling by a distinct neuronal and enteroendocrine AstA cell subset adapts the fly to a digestive energy-saving state which can be modulated by PDF.
KW - neurons
KW - neuroimaging
KW - circadian rhythms
KW - food consumption
KW - sleep
KW - biological locomotion
KW - Drosophila melanogaster
KW - signal peptides
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178170
VL - 12
IS - 9
ER -
TY - JOUR
A1 - Cavari, Benzion
A1 - Hong, Yunhan
A1 - Funkenstein, Bruria
A1 - Moav, Boaz
A1 - Schartl, Manfred
T1 - All-fish gene constructs for growth hormone gene transfer in fish
N2 - In order to develop all-fish expression vectors for microinjection into fertilized fish eggs, we have prepared the following cunstructs: rainbow trout metallothionein a/b and the gilthead seabream growth hormone cDNA (ptMTa-gbsGHcDNA, ptMTb-gsbGHcDNA), carp ß-actin gilthead seabream GH cDNA (pcAßgsbGHcDNA). The inducible metallothionein promoters a and b were cloned from rainbow trout, and the constitutive promoter ß-actin was isolated from carp. The metallothionein promoters were cloned by using the PCR technique. The tMTa contains 430 bp, while the tMTb contains 260 bp (Hong et al. 1992). These two promoters were introduced to pGEM-3Z containing the GH cDNA of Sparus aurata to form ptMTa-gsbGH and ptMTb-gsbGH, respectively. The carp cytoplasmic ß-actin gene was chosen as a source for isolating strong constitutive regulatory sequences. One of these regulatory sequences in pUC118 was Iigated to GH cDNA of S. aurata to form the pcAß-gsbGHcDNA. Expression of the constructs containing the metallothionein promoters was tested in fish cell culture and was found tobe induced effectively by zinc. The ptMTa gsb-GH cDNA construct was microinjected into fertilized carp eggs, and integration in the genome of carp was detected in the DNA isolated from fins at the age of two months.
KW - Physiologische Chemie
KW - growth hormone gene
KW - all-fish genes
KW - transgenic fish
KW - cellline transfection
KW - Sparus aurata
Y1 - 1993
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61612
ER -
TY - JOUR
A1 - Vikuk, Veronika
A1 - Fuchs, Benjamin
A1 - Krischke, Markus
A1 - Mueller, Martin J.
A1 - Rueb, Selina
A1 - Krauss, Jochen
T1 - Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods—A Re-Evaluation of Intoxication Risk in Germany?
JF - Journal of Fungi
N2 - Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable.
KW - Epichloë
KW - Lolium perenne
KW - toxicity
KW - grasslands
KW - HPLC/UPLC methods
KW - endophyte
KW - plant fresh/dry weight
KW - alkaloid detection methods
KW - mycotoxins
KW - phenology
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-213171
SN - 2309-608X
VL - 6
IS - 3
ER -
TY - JOUR
A1 - Breeze, Tom D.
A1 - Vaissiere, Bernhard E.
A1 - Bommarco, Riccardo
A1 - Petanidou, Theodora
A1 - Seraphides, Nicos
A1 - Kozak, Lajos
A1 - Scheper, Jeroen
A1 - Biesmeijer, Jacobus C.
A1 - Kleijn, David
A1 - Gyldenkærne, Steen
A1 - Moretti, Marco
A1 - Holzschuh, Andrea
A1 - Steffan-Dewenter, Ingolf
A1 - Stout, Jane C.
A1 - Pärtel, Meelis
A1 - Zobel, Martin
A1 - Potts, Simon G.
T1 - Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe
JF - PLOS ONE
N2 - Declines in insect pollinators across Europe have raised concerns about the supply of pollination services to agriculture. Simultaneously, EU agricultural and biofuel policies have encouraged substantial growth in the cultivated area of insect pollinated crops across the continent. Using data from 41 European countries, this study demonstrates that the recommended number of honeybees required to provide crop pollination across Europe has risen 4.9 times as fast as honeybee stocks between 2005 and 2010. Consequently, honeybee stocks were insufficient to supply >90% of demands in 22 countries studied. These findings raise concerns about the capacity of many countries to cope with major losses of wild pollinators and highlight numerous critical gaps in current understanding of pollination service supplies and demands, pointing to a pressing need for further research into this issue.
KW - economy services
KW - fruit set
KW - sequential introduction
KW - enhance
KW - biodiversity
KW - abundance
KW - declines
KW - crops
KW - colonies
KW - density
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117692
SN - 1932-6203
VL - 9
IS - 1
ER -
TY - JOUR
A1 - Lasway, Julius V.
A1 - Peters, Marcell K.
A1 - Njovu, Henry K.
A1 - Eardley, Connal
A1 - Pauly, Alain
A1 - Steffan‐Dewenter, Ingolf
T1 - Agricultural intensification with seasonal fallow land promotes high bee diversity in Afrotropical drylands
JF - Journal of Applied Ecology
N2 - The exponential increase in the human population in tandem with increased food demand has caused agriculture to be the global‐dominant form of land use. Afrotropical drylands are currently facing the loss of natural savannah habitats and agricultural intensification with largely unknown consequences for bees. Here we investigate the effects of agricultural intensification on bee assemblages in the Afrotropical drylands of northern Tanzania. We disentangled the direct effects of agricultural intensification and temperature on bee richness from indirect effects mediated by changes in floral resources.
We collected data from 24 study sites representing three levels of management intensity (natural savannah, moderate intensive and highly intensive agriculture) spanning an extensive gradient of mean annual temperature (MAT) in northern Tanzania. We used ordinary linear models and path analysis to test the effects of agricultural intensity and MAT on bee species richness, bee species composition and body‐size variation of bee communities.
We found that bee species richness increased with agricultural intensity and with increasing temperature. The effects of agricultural intensity and temperature on bee species richness were mediated by the positive effects of agriculture and temperature on the richness of floral resources used by bees. During the off‐growing season, agricultural land was characterized by an extensive period of fallow land holding a very high density of flowering plants with unique bee species composition. The increase in bee diversity in agricultural habitats paralleled an increasing variation of bee body sizes with agricultural intensification that, however, diminished in environments with higher temperatures.
Synthesis and applications. Our study reveals that bee assemblages in Afrotropical drylands benefit from agricultural intensification in the way it is currently practiced. However, further land‐use intensification, including year‐round irrigated crop monocultures and excessive use of agrochemicals, is likely to exert a negative impact on bee diversity and pollination services, as reported in temperate regions. Moreover, several bee species were restricted to natural savannah habitats. To conserve bee communities and guarantee pollination services in the region, a mixture of savannah and agriculture, with long periods of fallow land should be maintained.
KW - bee abundance
KW - bee body size
KW - bee species richness
KW - forage resources
KW - inter‐tegular distance
KW - mean annual temperature
KW - northern Tanzania
KW - species community composition
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-311877
VL - 59
IS - 12
SP - 3014
EP - 3026
ER -
TY - JOUR
A1 - Becker, Nils
A1 - Kucharski, Robert
A1 - Rössler, Wolfgang
A1 - Maleszka, Ryszard
T1 - Age‐dependent transcriptional and epigenomic responses to light exposure in the honey bee brain
JF - FEBS Open Bio
N2 - Light is a powerful environmental stimulus of special importance in social honey bees that undergo a behavioral transition from in-hive to outdoor foraging duties. Our previous work has shown that light exposure induces structural neuronal plasticity in the mushroom bodies (MBs), a brain center implicated in processing inputs from sensory modalities. Here, we extended these analyses to the molecular level to unravel light-induced transcriptomic and epigenomic changes in the honey bee brain. We have compared gene expression in brain compartments of 1- and 7-day-old light-exposed honey bees with age-matched dark-kept individuals. We have found a number of differentially expressed genes (DEGs), both novel and conserved, including several genes with reported roles in neuronal plasticity. Most of the DEGs show age-related changes in the amplitude of light-induced expression and are likely to be both developmentally and environmentally regulated. Some of the DEGs are either known to be methylated or are implicated in epigenetic processes suggesting that responses to light exposure are at least partly regulated at the epigenome level. Consistent with this idea light alters the DNA methylation pattern of bgm, one of the DEGs affected by light exposure, and the expression of microRNA miR-932. This confirms the usefulness of our approach to identify candidate genes for neuronal plasticity and provides evidence for the role of epigenetic processes in driving the molecular responses to visual stimulation.
KW - DNA methylation
KW - insect brain
KW - light-induced gene expression
KW - microRNA
KW - neuronal plasticity
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147080
VL - 6
IS - 7
ER -
TY - JOUR
A1 - Dandekar, Thomas
A1 - Gramsch, Christian
A1 - Houghton, Richard A.
A1 - Schultz, Rüdiger
T1 - Affinity purification of \(\beta\)-endorphin-like material from NG108CC15 cells by means of the monoclonal \(\beta\)-endorphin antibody 3-E7
N2 - No abstract available
Y1 - 1985
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29896
ER -
TY - JOUR
A1 - Riedmeier, Maria
A1 - Decarolis, Boris
A1 - Haubitz, Imme
A1 - Müller, Sophie
A1 - Uttinger, Konstantin
A1 - Börner, Kevin
A1 - Reibetanz, Joachim
A1 - Wiegering, Armin
A1 - Härtel, Christoph
A1 - Schlegel, Paul-Gerhardt
A1 - Fassnacht, Martin
A1 - Wiegering, Verena
T1 - Adrenocortical carcinoma in childhood: a systematic review
JF - Cancers
N2 - Adrenocortical tumors are rare in children. This systematic review summarizes the published evidence on pediatric adrenocortical carcinoma (ACC) to provide a basis for a better understanding of the disease, investigate new molecular biomarkers and therapeutic targets, and define which patients may benefit from a more aggressive therapeutic approach. We included 137 studies with 3680 ACC patients (~65% female) in our analysis. We found no randomized controlled trials, so this review mainly reflects retrospective data. Due to a specific mutation in the TP53 gene in ~80% of Brazilian patients, that cohort was analyzed separately from series from other countries. Hormone analysis was described in 2569 of the 2874 patients (89%). Most patients were diagnosed with localized disease, whereas 23% had metastasis at primary diagnosis. Only 72% of the patients achieved complete resection. In 334 children (23%), recurrent disease was reported: 81% — local recurrence, 19% (n = 65) — distant metastases at relapse. Patients < 4 years old had a different distribution of tumor stages and hormone activity and better overall survival (p < 0.001). Although therapeutic approaches are typically multimodal, no consensus is available on effective standard treatments for advanced ACC. Thus, knowledge regarding pediatric ACC is still scarce and international prospective studies are needed to implement standardized clinical stratifications and risk-adapted therapeutic strategies.
KW - pediatric adrenocortical cancer
KW - pediatric adrenocortical adenoma
KW - pediatric adrenocortical tumor
KW - prognostic factors
KW - therapy
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-248507
SN - 2072-6694
VL - 13
IS - 21
ER -
TY - JOUR
A1 - Uttinger, Konstantin L.
A1 - Riedmeier, Maria
A1 - Reibetanz, Joachim
A1 - Meyer, Thomas
A1 - Germer, Christoph Thomas
A1 - Fassnacht, Martin
A1 - Wiegering, Armin
A1 - Wiegering, Verena
T1 - Adrenalectomies in children and adolescents in Germany – a diagnose related groups based analysis from 2009-2017
JF - Frontiers in Endocrinology
N2 - Background
Adrenalectomies are rare procedures especially in childhood. So far, no large cohort study on this topic has been published with data on to age distribution, operative procedures, hospital volume and operative outcome.
Methods
This is a retrospective analysis of anonymized nationwide hospital billing data (DRG data, 2009-2017). All adrenal surgeries (defined by OPS codes) of patients between the age 0 and 21 years in Germany were included.
Results
A total of 523 patient records were identified. The mean age was 8.6 ± 7.7 years and 262 patients were female (50.1%). The majority of patients were between 0 and 5 years old (52% overall), while 11.1% were between 6 and 11 and 38.8% older than 12 years. The most common diagnoses were malignant neoplasms of the adrenal gland (56%, mostly neuroblastoma) with the majority being younger than 5 years. Benign neoplasms in the adrenal gland (D350) account for 29% of all cases with the majority of affected patients being 12 years or older. 15% were not defined regarding tumor behavior. Overall complication rate was 27% with a clear higher complication rate in resection for malignant neoplasia of the adrenal gland. Bleeding occurrence and transfusions are the main complications, followed by the necessary of relaparotomy. There was an uneven patient distribution between hospital tertiles (low volume, medium and high volume tertile). While 164 patients received surgery in 85 different “low volume” hospitals (0.2 cases per hospital per year), 205 patients received surgery in 8 different “high volume” hospitals (2.8 cases per hospital per year; p<0.001). Patients in high volume centers were significant younger, had more extended resections and more often malignant neoplasia. In multivariable analysis younger age, extended resections and open procedures were independent predictors for occurrence of postoperative complications.
Conclusion
Overall complication rate of adrenalectomies in the pediatric population in Germany is low, demonstrating good therapeutic quality. Our analysis revealed a very uneven distribution of patient volume among hospitals.
KW - pediatric
KW - neuroblastoma – diagnosis
KW - therapy
KW - adrenocortical adenocarcinoma
KW - outcome
KW - volume
KW - adrenalectomia
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-282280
SN - 1664-2392
VL - 13
ER -
TY - JOUR
A1 - Grund-Mueller, Nils
A1 - Ruedenauer, Fabian A.
A1 - Spaethe, Johannes
A1 - Leonhardt, Sara D.
T1 - Adding amino acids to a sucrose diet is not sufficient to support longevity of adult bumble bees
JF - Insects
N2 - Dietary macro-nutrients (i.e., carbohydrates, protein, and fat) are important for bee larval development and, thus, colony health and fitness. To which extent different diets (varying in macro-nutrient composition) affect adult bees and whether they can thrive on nectar as the sole amino acid source has, however, been little investigated. We investigated how diets varying in protein concentration and overall nutrient composition affected consumption, longevity, and breeding behavior of the buff-tailed bumble bee, Bombus terrestris (Hymenoptera: Apidae). Queenless micro-colonies were fed either natural nutrient sources (pollen), nearly pure protein (i.e., the milk protein casein), or sucrose solutions with low and with high essential amino acid content in concentrations as can be found in nectar. We observed micro-colonies for 110 days. We found that longevity was highest for pure pollen and lowest for pure sucrose solution and sucrose solution supplemented with amino acids in concentrations as found in the nectar of several plant species. Adding higher concentrations of amino acids to sucrose solution did only slightly increase longevity compared to sucrose alone. Consequently, sucrose solution with the applied concentrations and proportions of amino acids or other protein sources (e.g., casein) alone did not meet the nutritional needs of healthy adult bumble bees. In fact, longevity was highest and reproduction only successful in micro-colonies fed pollen. These results indicate that, in addition to carbohydrates and protein, adult bumble bees, like larvae, need further nutrients (e.g., lipids and micro-nutrients) for their well-being. An appropriate nutritional composition seemed to be best provided by floral pollen, suggesting that pollen is an essential dietary component not only for larvae but also for adult bees.
KW - nutrition
KW - nutrients
KW - foraging
KW - pollen
KW - resources
KW - adult bees
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203866
SN - 2075-4450
VL - 11
IS - 4
ER -
TY - JOUR
A1 - Mitesser, Oliver
A1 - Weissel, Norbert
A1 - Strohm, Erhard
A1 - Poethke, Hans-Joachim
T1 - Adaptive dynamic resource allocation in annual eusocial insects: Environmental variation will not necessarily promote graded control
N2 - Background: According to the classical model of Macevicz and Oster, annual eusocial insects should show a clear dichotomous "bang-bang" strategy of resource allocation; colony fitness is maximised when a period of pure colony growth (exclusive production of workers) is followed by a single reproductive period characterised by the exclusive production of sexuals. However, in several species graded investment strategies with a simultaneous production of workers and sexuals have been observed. Such deviations from the "bang-bang" strategy are usually interpreted as an adaptive (bet-hedging) response to environmental fluctuations such as variation in season length or food availability. To generate predictions about the optimal investment pattern of insect colonies in fluctuating environments, we slightly modified Macevicz and Oster's classical model of annual colony dynamics and used a dynamic programming approach nested into a recurrence procedure for the solution of the stochastic optimal control problem. Results: 1) The optimal switching time between pure colony growth and the exclusive production of sexuals decreases with increasing environmental variance. 2) Yet, for reasonable levels of environmental fluctuations no deviation from the typical bang-bang strategy is predicted. 3) Model calculations for the halictid bee Lasioglossum malachurum reveal that bet-hedging is not likely to be the reason for the graded allocation into sexuals versus workers observed in this species. 4) When environmental variance reaches a critical level our model predicts an abrupt change from dichotomous behaviour to graded allocation strategies, but the transition between colony growth and production of sexuals is not necessarily monotonic. Both, the critical level of environmental variance as well as the characteristic pattern of resource allocation strongly depend on the type of function used to describe environmental fluctuations. Conclusion: Up to now bet-hedging as an evolutionary response to variation in season length has been the main argument to explain field observations of graded resource allocation in annual eusocial insect species. However, our model shows that the effect of moderate fluctuations of environmental conditions does not select for deviation from the classical bang-bang strategy and that the evolution of graded allocation strategies can be triggered only by extreme fluctuations. Detailed quantitative observations on resource allocation in eusocial insects are needed to analyse the relevance of alternative explanations, e.g. logistic colony growth or reproductive conflict between queen and workers, for the evolution of graded allocation strategies.
KW - Insekten
KW - Fitness
KW - Evolution
KW - Sozialität
KW - resource allocation
KW - fitness
KW - evolution
KW - eusociality
KW - insect
Y1 - 2007
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45412
ER -
TY - JOUR
A1 - Kobelt, Frank
A1 - Linsenmair, Karl Eduard
T1 - Adaptations of the reed frog Hyperolius viridiflavus to its arid environment. I. The skin of Hyperolius viridiflavus nitidulus in wet and dry season conditions.
N2 - Hyperolius viridiflavus nitidulus inhabits parts of the seasonally very hot and dry West African savanna. During the long lasting dry season, the small frog is sitting unhidden on mostly dry plants and has to deal with high solar radiation load (SRL), evaporative water loss (EWL) and small energy reserves. It seems to be very badly equipped to survive such harsh climatic conditions (unfavorable surface to volume ratio, very limited capacity to störe energy and water). Therefore, it must have developed extraordinary efficient mechanisms to solve the mentioned Problems. Some of these mechanisms are to be looked for within the skin of the animal (e.g. protection against fast desiccation, deleterious effects of UV radiation and over-heating). The morphology of the wet season skin is, in most aspects, that of a "normal" anuran skin. It differs in the Organization of the processes of the melanophores and in the arrangement of the chromatophores in the Stratum spongiosum, forming no "Dermal Chromatophore Unit". During the adaptation to dry season conditions the number of iridophores in dorsal and ventral skin is increased 4-6 times compared to wet season skin. This increase is accompanied by a very conspicuous change of the wet season color pattern. Now, at air temperatures below 35° C the color becomes brownish white or grey and changes to a brilliant white at air temperatures near and over 40° C. Thus, in dry season State the frog retains its ability for rapid color change. In wet season State the platelets of the iridophores are irregularly distributed. In dry season State many platelets become arranged almost parallel to the surface. These purine crystals probably act as quarter-wave-length interference reflectors, reducing SRL by reflecting a considerable amount of the radiated energy input. EWL is as low as that of much larger xeric reptilians. The impermeability of the skin seems to be the result of several mechanisms (ground substance, iridophores, lipids, mucus) supplementing each other. The light red skin at the pelvic region and inner sides of the limbs is specialized for rapid uptake of water allowing the frog to replenish the unavoidable EWL by using single drops of dew or rain, available for only very short periods.
Y1 - 1986
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30551
ER -
TY - JOUR
A1 - Kobelt, F.
A1 - Linsenmair, Karl Eduard
T1 - Adaptations of the reed frog Hyperolius viridiflavus (Hyperoliidae) to its arid environment. VI. The iridophores in the skin as radiation reflectors
N2 - No abstract available
Y1 - 1992
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30563
ER -
TY - JOUR
A1 - Linsenmair, Karl Eduard
T1 - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment: II. Some aspects of the water economy of H. viridiflavus nitidulus under wet and dry ...
N2 - Adaptations to aridity ofthe reedfrog Hyperolius viridiflavus nitidulus, living in different parts of the seasonally very dry and hot West African savanna, are investigated ...
KW - Zoologie
Y1 - 1986
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78395
ER -
TY - JOUR
A1 - Geise, W.
A1 - Linsenmair, Karl Eduard
T1 - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. IV. Ecological significance of water economy with comments on thermoregulation and energy allocation
N2 - No abstract available
Y1 - 1988
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30570
ER -
TY - JOUR
A1 - Linsenmair, Karl Eduard
A1 - Schmuck, R.
T1 - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. III. Aspects of nitrogen metabolism and osmuregulation in the reed frog, H. viridiflavus taeniatus, with special reference to the role of iridophores
N2 - Reed frogs of the superspecies Hyperolius viridiflavus occur throughout the seasonally very dry and hot African savannas. Despite their small size (300-700 mg), estivating reed frogs do not avoid stressful conditions above ground by burrowing into the soil, but endure the inhospitable climate relatively unprotected, clinging to mostly dry grass sterns. They must have emcient mechanisms to enable them to survive e.g. very high temperatures, low relative hurnidities, and high solar radiation loads. Mechanisms must also have developed to prevent poisoning by the nitrogenous wastes that inevitably result from protein and nucleotide turnover. In contrast to fossorial amphibians, estivating reed frogs do not become torpid. Reduction in metabolism is therefore rather Iimited so that nitrogenous wastes accumulate faster in these frogs than in fossorial amphibians. This severely aggravates the osmotic problems caused by dehydration. During dry periods total plasma osmolarity greatly increases, mainly due to urea accumulation. Of the total urea accumulated over 42 days of experimental water deprivation, 30% was produced during the first 7 days. In the next 7 days rise in plasma urea content was negligible. This strong initial increase of urea is seen as a byproduct of elevated amino acid catabolism following the onset of dry conditions. Tbe rise in total plasma osmolarity due to urea accumulation, however, is not totally disadvantageous, but enables fast rehydration when water is available for very short periods only. Voiding of urine and feces eeases once evaporative water loss exceeds 10% of body weight. Tberefore, during continuous water deprivation, nitrogenous end products are not excreted. After 42 days of water deprivation, bladder fluid was substantially depleted, and urea coneentration in the remaining urine (up to 447 mM) was never greater than in plasma fluid. Feces voided at the end of the dry period after water uptake contained only small amounts of nitrogenous end products. DSF (dry season frogs) seemed not to be uricotelic. Instead, up to 35% of the total nitrogenous wastes produced over 42 days of water deprivation were deposited in an osmotically inert and nontoxic form in iridophore crystals. The increase in skin purine content averaged 150 µg/mg dry weight. If urea had been the only nitrogenous waste product during an estivation period of 42 days, lethal limits of total osmolarity (about 700 mOsm) would have been reached 10-14 days earlier. Thus iridophores are not only involved in colour change and in reducing heat load by radiation remission, but are also important in osmoregulation during dry periods. The seIective advantages of deposition of guanine rather than uric acid are discussed.
KW - Biologie
KW - Zoologie
KW - Frosch
KW - Hyperolius viridiflavus
KW - Estivation
KW - Osmoregulation
KW - Nitrogen metabolism
KW - lridophores
Y1 - 1988
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78108
ER -
TY - JOUR
A1 - Schmuck, R.
A1 - Kobelt, F.
A1 - Linsenmair, Karl Eduard
T1 - Adaptations of the reed frog Hyperbolius viridiflavus (Anura, Hyperbolidae) to its arid environment: V. Iridophores and nitrogen metabolism
N2 - Ofall amphibians living in arid habitats, reed frogs (belonging to the super species Hyperolius viridiflavus) are the most peculiar. Froglets are able to tolerate dry periods of up to 35 days or longer immediately after metamorphosis, in climatically exposed positions. They face similar problems to estivating juveniles, i.e. enduranee of long periods of high temperature and low RH with rather limited energy and water reserves. In addition, they must have had to develop meehanisms to prevent poisoning by nitrogenous wastes that rapidly accumulate during dry periods as a metabolie consequenee of maintaining a non-torpid state. During dry periods, plasma osmolarity of H. v. taeniatus froglets strongly increased, mainly through urea accumulation. Urea accumulation was also observed during metamorphic climax. During postmetamorphic growth, chromatophores develop with the density and morphology typical of the adult pigmentary pattern. The dermal iridophore layer, which is still incomplete at this time, is fully developed within 4-8 days after metamorphosis, irrespective of maintenance conditions. These iridophores mainly contain the purines guanine and hypoxanthine. The ability of these purines to reflect light provides an excellent basis for the role of iridophores in temperature regulation. In individuals experiencing dehydration stress, the initial rate of purine synthesis is doubled in eomparison to specimens continuously maintained under wet season conditions. This increase in synthesis rate leads to a rapid increase in the thiekness of the iridophore layer, thereby effectively reducing radiation absorption. Thus, the danger of overheating is diminished during periods of water shortage when evaporative cooling must be avoided. After the development of an iridophore layer of sufficient thickness for effective radiation reflectance, synthesis of iridophore pigments does not cease. Rather, this pathway is further used during the remaining dry season for solving osmotic problems eaused by accumulation of nitrogenous wastes. During prolonged water deprivation, in spite of reduced metabolic rates, purine pigments are produced at the same rate as in wet season conditions. This leads to a higher relative proportion of nitrogen end products being stored in skin pigments under dry season conditions. At the end of an experimental dry season lasting 35 days, up to 38% of the accrued nitrogen is stored in the form of osmotically inactive purines in thc skin. Thus the osmotic problems caused by evaporative water loss and urea production are greatly reduced.
KW - Biologie
KW - Zoologie
KW - Frosch
Y1 - 1988
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78094
ER -
TY - JOUR
A1 - Kessie, David K.
A1 - Lodes, Nina
A1 - Oberwinkler, Heike
A1 - Goldman, William E.
A1 - Walles, Thorsten
A1 - Steinke, Maria
A1 - Gross, Roy
T1 - Activity of Tracheal Cytotoxin of Bordetella pertussis in a Human Tracheobronchial 3D Tissue Model
JF - Frontiers in Cellular and Infection Microbiology
N2 - Bordetella pertussis is a highly contagious pathogen which causes whooping cough in humans. A major pathophysiology of infection is the extrusion of ciliated cells and subsequent disruption of the respiratory mucosa. Tracheal cytotoxin (TCT) is the only virulence factor produced by B. pertussis that has been able to recapitulate this pathology in animal models. This pathophysiology is well characterized in a hamster tracheal model, but human data are lacking due to scarcity of donor material. We assessed the impact of TCT and lipopolysaccharide (LPS) on the functional integrity of the human airway mucosa by using in vitro airway mucosa models developed by co-culturing human tracheobronchial epithelial cells and human tracheobronchial fibroblasts on porcine small intestinal submucosa scaffold under airlift conditions. TCT and LPS either alone and in combination induced blebbing and necrosis of the ciliated epithelia. TCT and LPS induced loss of ciliated epithelial cells and hyper-mucus production which interfered with mucociliary clearance. In addition, the toxins had a disruptive effect on the tight junction organization, significantly reduced transepithelial electrical resistance and increased FITC-Dextran permeability after toxin incubation. In summary, the results indicate that TCT collaborates with LPS to induce the disruption of the human airway mucosa as reported for the hamster tracheal model.
KW - tracheal cytotoxin
KW - airway epithelia
KW - tissue model
KW - ciliostasis
KW - tight junction
KW - Bordetella pertussis
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222736
SN - 2235-2988
VL - 10
ER -
TY - JOUR
A1 - Mrestani, Achmed
A1 - Pauli, Martin
A1 - Kollmannsberger, Philip
A1 - Repp, Felix
A1 - Kittel, Robert J.
A1 - Eilers, Jens
A1 - Doose, Sören
A1 - Sauer, Markus
A1 - Sirén, Anna-Leena
A1 - Heckmann, Manfred
A1 - Paul, Mila M.
T1 - Active zone compaction correlates with presynaptic homeostatic potentiation
JF - Cell Reports
N2 - Neurotransmitter release is stabilized by homeostatic plasticity. Presynaptic homeostatic potentiation (PHP) operates on timescales ranging from minute- to life-long adaptations and likely involves reorganization of presynaptic active zones (AZs). At Drosophila melanogaster neuromuscular junctions, earlier work ascribed AZ enlargement by incorporating more Bruchpilot (Brp) scaffold protein a role in PHP. We use localization microscopy (direct stochastic optical reconstruction microscopy [dSTORM]) and hierarchical density-based spatial clustering of applications with noise (HDBSCAN) to study AZ plasticity during PHP at the synaptic mesoscale. We find compaction of individual AZs in acute philanthotoxin-induced and chronic genetically induced PHP but unchanged copy numbers of AZ proteins. Compaction even occurs at the level of Brp subclusters, which move toward AZ centers, and in Rab3 interacting molecule (RIM)-binding protein (RBP) subclusters. Furthermore, correlative confocal and dSTORM imaging reveals how AZ compaction in PHP translates into apparent increases in AZ area and Brp protein content, as implied earlier.
KW - active zone
KW - Bruchpilot
KW - RIM-binding protein
KW - compaction
KW - homeostasis
KW - presynaptic plasticity
KW - super-resolution microscopy
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265497
VL - 37
IS - 1
ER -
TY - JOUR
A1 - Prusty, Bhupesh K.
A1 - Gulve, Nitish
A1 - Govind, Sheila
A1 - Krueger, Gerhard R. F.
A1 - Feichtinger, Julia
A1 - Larcombe, Lee
A1 - Aspinall, Richard
A1 - Ablashi, Dharam V.
A1 - Toro, Carla T.
T1 - Active HHV-6 Infection of Cerebellar Purkinje Cells in Mood Disorders
JF - Frontiers in Microbiology
N2 - Early-life infections and associated neuroinflammation is incriminated in the pathogenesis of various mood disorders. Infection with human roseoloviruses, HHV-6A and HHV-6B, allows viral latency in the central nervous system and other tissues, which can later be activated causing cognitive and behavioral disturbances. Hence, this study was designed to evaluate possible association of HHV-6A and HHV-6B activation with three different groups of psychiatric patients. DNA qPCR, immunofluorescence and FISH studies were carried out in post-mortem posterior cerebellum from 50 cases each of bipolar disorder (BPD), schizophrenia, 15 major depressive disorder (MDD) and 50 appropriate control samples obtained from two well-known brain collections (Stanley Medical Research Institute). HHV-6A and HHV-6B late proteins (indicating active infection) and viral DNA were detected more frequently (p < 0.001 for each virus) in human cerebellum in MDD and BPD relative to controls. These roseolovirus proteins and DNA were found less frequently in schizophrenia cases. Active HHV-6A and HHV-6B infection in cerebellar Purkinje cells were detected frequently in BPD and MDD cases. Furthermore, we found a significant association of HHV-6A infection with reduced Purkinje cell size, suggesting virus-mediated abnormal Purkinje cell function in these disorders. Finally, gene expression analysis of cerebellar tissue revealed changes in pathways reflecting an inflammatory response possibly to HHV-6A infection. Our results provide molecular evidence to support a role for active HHV-6A and HHV-6B infection in BPD and MDD.
KW - HHV-6
KW - bipolar disorder
KW - schizophrenia
KW - major depressive disorder
KW - Purkinje cells
Y1 - 2018
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-369222
VL - 9
ER -
TY - JOUR
A1 - Barnekow, Angelika
A1 - Gessler, Manfred
T1 - Activation of the pp60\(^{c-src}\) kinase during differentiation of monomyelocytic cells in vitro
N2 - Tbe proto-oncogene c-src, the cellular homolog of the Rous sarcoma virus (RSV) transforming gene v-src, is expressed in a tissue-specific and age-dependent manner. Its physiological function, although still unknown, appears to be more closely related to differentiation processes than to proliferation processes. To obtain more information about the physiological role of the c-src gene in cells, we have studied differentiation-dependent alterations using the human HL-60 leukaemia cell line as a model system. Induction of monocytic and granulocytic differentiation of HL-60 cells by 12-0-tetradecanoylphorbol-13-acetate (TPA) and dimethylsulfoxide (DMSO) is associated with an activation of the pp60c-src tyrosine kinase, but not with increased c-src gene expression. Control experiments exclude an interaction of TPA and DMSO themselves with the pp60c-src kinase.
KW - Biochemie
KW - c-src
KW - differentiation
KW - protein tyrosine kinase
KW - protooncogene
Y1 - 1986
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59278
ER -
TY - JOUR
A1 - Rosenbaum, Corinna
A1 - Schick, Martin Alexander
A1 - Wollborn, Jakob
A1 - Heider, Andreas
A1 - Scholz, Claus-Jürgen
A1 - Cecil, Alexander
A1 - Niesler, Beate
A1 - Hirrlinger, Johannes
A1 - Walles, Heike
A1 - Metzger, Marco
T1 - Activation of Myenteric Glia during Acute Inflammation In Vitro and In Vivo
JF - PLoS One
N2 - Background
Enteric glial cells (EGCs) are the main constituent of the enteric nervous system and share similarities with astrocytes from the central nervous system including their reactivity to an inflammatory microenvironment. Previous studies on EGC pathophysiology have specifically focused on mucosal glia activation and its contribution to mucosal inflammatory processes observed in the gut of inflammatory bowel disease (IBD) patients. In contrast knowledge is scarce on intestinal inflammation not locally restricted to the mucosa but systemically affecting the intestine and its effect on the overall EGC network.
Methods and Results
In this study, we analyzed the biological effects of a systemic LPS-induced hyperinflammatory insult on overall EGCs in a rat model in vivo, mimicking the clinical situation of systemic inflammation response syndrome (SIRS). Tissues from small and large intestine were removed 4 hours after systemic LPS-injection and analyzed on transcript and protein level. Laser capture microdissection was performed to study plexus-specific gene expression alterations. Upon systemic LPS-injection in vivo we observed a rapid and dramatic activation of Glial Fibrillary Acidic Protein (GFAP)-expressing glia on mRNA level, locally restricted to the myenteric plexus. To study the specific role of the GFAP subpopulation, we established flow cytometry-purified primary glial cell cultures from GFAP promotor-driven EGFP reporter mice. After LPS stimulation, we analyzed cytokine secretion and global gene expression profiles, which were finally implemented in a bioinformatic comparative transcriptome analysis. Enriched GFAP+ glial cells cultured as gliospheres secreted increased levels of prominent inflammatory cytokines upon LPS stimulation. Additionally, a shift in myenteric glial gene expression profile was induced that predominantly affected genes associated with immune response.
Conclusion and Significance
Our findings identify the myenteric GFAP-expressing glial subpopulation as particularly susceptible and responsive to acute systemic inflammation of the gut wall and complement knowledge on glial involvement in mucosal inflammation of the intestine.
KW - gene expression
KW - gastrointestinal tract
KW - inflammatory bowel disease
KW - central nervous system
KW - systemic inflammatory response syndrome
KW - inflammation
KW - astrocytes
KW - cytokines
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146544
VL - 11
IS - 3
ER -
TY - JOUR
A1 - Garitano-Trojaola, Andoni
A1 - Sancho, Ana
A1 - Götz, Ralph
A1 - Eiring, Patrick
A1 - Walz, Susanne
A1 - Jetani, Hardikkumar
A1 - Gil-Pulido, Jesus
A1 - Da Via, Matteo Claudio
A1 - Teufel, Eva
A1 - Rhodes, Nadine
A1 - Haertle, Larissa
A1 - Arellano-Viera, Estibaliz
A1 - Tibes, Raoul
A1 - Rosenwald, Andreas
A1 - Rasche, Leo
A1 - Hudecek, Michael
A1 - Sauer, Markus
A1 - Groll, Jürgen
A1 - Einsele, Hermann
A1 - Kraus, Sabrina
A1 - Kortüm, Martin K.
T1 - Actin cytoskeleton deregulation confers midostaurin resistance in FLT3-mutant acute myeloid leukemia
JF - Communications Biology
N2 - The presence of FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with an unfavorable prognosis. FLT3 inhibitors, such as midostaurin, are used clinically but fail to entirely eradicate FLT3-ITD+AML. This study introduces a new perspective and highlights the impact of RAC1-dependent actin cytoskeleton remodeling on resistance to midostaurin in AML. RAC1 hyperactivation leads resistance via hyperphosphorylation of the positive regulator of actin polymerization N-WASP and antiapoptotic BCL-2. RAC1/N-WASP, through ARP2/3 complex activation, increases the number of actin filaments, cell stiffness and adhesion forces to mesenchymal stromal cells (MSCs) being identified as a biomarker of resistance. Midostaurin resistance can be overcome by a combination of midostaruin, the BCL-2 inhibitor venetoclax and the RAC1 inhibitor Eht1864 in midostaurin-resistant AML cell lines and primary samples, providing the first evidence of a potential new treatment approach to eradicate FLT3-ITD+AML. Garitano-Trojaola et al. used a combination of human acute myeloid leukemia (AML) cell lines and primary samples to show that RAC1-dependent actin cytoskeleton remodeling through BCL2 family plays a key role in resistance to the FLT3 inhibitor, Midostaurin in AML. They showed that by targeting RAC1 and BCL2, Midostaurin resistance was diminished, which potentially paves the way for an innovate treatment approach for FLT3 mutant AML.
KW - actin
KW - acute myeloid leukaemia
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260709
VL - 4
IS - 1
ER -
TY - JOUR
A1 - Eckert, W. A.
A1 - Franke, Werner W.
A1 - Scheer, Ulrich
T1 - Actinomycin D and the central granules in the nuclear pore complex: thin sectioning versus negative staining
N2 - Thin section electron microscopy of Actinomycin D treated Tetrahymena cells and amphibian oocytes (Xenopus laevis, Triturus aZpestris) reveal no reduction in the central granules in the nuclear pore complexes. Possible reasons for the diversity between these results and earlier observations using negatively stained isolated nuclear envelopes from the same objects are discussed. The results clearly show that the presence of central granules within the nuclear pores does neither depend on nuclear RNA synthesis nor does indicate nucleocytoplasmic RNA transport. This conclusion leads to a reconsideration of the nature of the central granule. The functioning of the central granule of the nuclear pore complexes is further discussed in connection with recent studies on the ultrastructure of various types of cisternal pores.
KW - Nuclear pores
KW - Nucleocytoplasmic exchange
KW - Actinomycin D
KW - Tetrahymena
KW - Amphibian oocytes
Y1 - 1972
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40636
ER -
TY - JOUR
A1 - Lehmann, Julian
A1 - Jørgensen, Morten E.
A1 - Fratz, Stefanie
A1 - Müller, Heike M.
A1 - Kusch, Jana
A1 - Scherzer, Sönke
A1 - Navarro-Retamal, Carlos
A1 - Mayer, Dominik
A1 - Böhm, Jennifer
A1 - Konrad, Kai R.
A1 - Terpitz, Ulrich
A1 - Dreyer, Ingo
A1 - Mueller, Thomas D.
A1 - Sauer, Markus
A1 - Hedrich, Rainer
A1 - Geiger, Dietmar
A1 - Maierhofer, Tobias
T1 - Acidosis-induced activation of anion channel SLAH3 in the flooding-related stress response of Arabidopsis
JF - Current Biology
N2 - Plants, as sessile organisms, gained the ability to sense and respond to biotic and abiotic stressors to survive severe changes in their environments. The change in our climate comes with extreme dry periods but also episodes of flooding. The latter stress condition causes anaerobiosis-triggered cytosolic acidosis and impairs plant function. The molecular mechanism that enables plant cells to sense acidity and convey this signal via membrane depolarization was previously unknown. Here, we show that acidosis-induced anion efflux from Arabidopsis (Arabidopsis thaliana) roots is dependent on the S-type anion channel AtSLAH3. Heterologous expression of SLAH3 in Xenopus oocytes revealed that the anion channel is directly activated by a small, physiological drop in cytosolic pH. Acidosis-triggered activation of SLAH3 is mediated by protonation of histidine 330 and 454. Super-resolution microscopy analysis showed that the increase in cellular proton concentration switches SLAH3 from an electrically silent channel dimer into its active monomeric form. Our results show that, upon acidification, protons directly switch SLAH3 to its open configuration, bypassing kinase-dependent activation. Moreover, under flooding conditions, the stress response of Arabidopsis wild-type (WT) plants was significantly higher compared to SLAH3 loss-of-function mutants. Our genetic evidence of SLAH3 pH sensor function may guide the development of crop varieties with improved stress tolerance.
KW - SLAH3
KW - S-type anion channel
KW - hypoxia
KW - pH
KW - cytosolic acidification
KW - flooding
KW - PALM
KW - stoichiometry
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-363320
VL - 31
ER -
TY - JOUR
A1 - Dedukh, Dmitrij
A1 - Da Cruz, Irene
A1 - Kneitz, Susanne
A1 - Marta, Anatolie
A1 - Ormanns, Jenny
A1 - Tichopád, Tomáš
A1 - Lu, Yuan
A1 - Alsheimer, Manfred
A1 - Janko, Karel
A1 - Schartl, Manfred
T1 - Achiasmatic meiosis in the unisexual Amazon molly, Poecilia formosa
JF - Chromosome Research
N2 - Unisexual reproduction, which generates clonal offspring, is an alternative strategy to sexual breeding and occurs even in vertebrates. A wide range of non-sexual reproductive modes have been described, and one of the least understood questions is how such pathways emerged and how they mechanistically proceed. The Amazon molly, Poecilia formosa, needs sperm from males of related species to trigger the parthenogenetic development of diploid eggs. However, the mechanism, of how the unreduced female gametes are produced, remains unclear. Cytological analyses revealed that the chromosomes of primary oocytes initiate pachytene but do not proceed to bivalent formation and meiotic crossovers. Comparing ovary transcriptomes of P. formosa and its sexual parental species revealed expression levels of meiosis-specific genes deviating from P. mexicana but not from P. latipinna. Furthermore, several meiosis genes show biased expression towards one of the two alleles from the parental genomes. We infer from our data that in the Amazon molly diploid oocytes are generated by apomixis due to a failure in the synapsis of homologous chromosomes. The fact that this failure is not reflected in the differential expression of known meiosis genes suggests the underlying molecular mechanism may be dysregulation on the protein level or misexpression of a so far unknown meiosis gene, and/or hybrid dysgenesis because of compromised interaction of proteins from diverged genomes.
KW - meiosis
KW - parthenogenesis
KW - synaptonemal complex
KW - recombination
KW - crossing-over
KW - achiasmatic
KW - transcriptome
KW - oogenesis
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-325128
VL - 30
IS - 4
ER -
TY - JOUR
A1 - Riedel, Alice
A1 - Mofolo, Boitumelo
A1 - Avota, Elita
A1 - Schneider-Schaulies, Sibylle
A1 - Meintjes, Ayton
A1 - Mulder, Nicola
A1 - Kneitz, Susanne
T1 - Accumulation of Splice Variants and Transcripts in Response to PI3K Inhibition in T Cells
JF - PLoS ONE
N2 - Background
Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA.
Hypothesis
Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing.
Methods
To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression.
Results
Applying our algorithm to the data, 9% of the genes were assigned as AS, while only 3% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry.
Conclusions
PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.
KW - T cells
KW - gene regulation
KW - alternative splicing
KW - measles virus
KW - T cell receptors
KW - reverse transcriptase-polymerase chain reaction
KW - cell cycle and cell division
KW - TCR signaling cascade
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130335
VL - 8
IS - 2
ER -
TY - JOUR
A1 - Riedel, Alice
A1 - Mofolo, Boitumelo
A1 - Avota, Elita
A1 - Schneider-Schaulies, Sibylle
A1 - Meintjes, Ayton
A1 - Mulder, Nicola
A1 - Kneitz, Susanne
T1 - Accumulation of Splice Variants and Transcripts in Response to PI3K Inhibition in T Cells
N2 - Background: Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis: Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods: To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results: Applying our algorithm to the data, 9% of the genes were assigned as AS, while only 3% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions: PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.
KW - Biologie
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-77917
ER -
TY - JOUR
A1 - Goebel, Werner
A1 - Kreft, Jürgen
T1 - Accumulation of replicative intermediates and catenated forms of the colicinogenic factor E\(_1\) in E. coli during the replication at elevated temperatures
N2 - No abstract available
KW - Biologie
Y1 - 1972
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60625
ER -
TY - JOUR
A1 - Vogel, Sebastian
A1 - Prinzing, Andreas
A1 - Bußler, Heinz
A1 - Müller, Jörg
A1 - Schmidt, Stefan
A1 - Thorn, Simon
T1 - Abundance, not diversity, of host beetle communities determines abundance and diversity of parasitoids in deadwood
JF - Ecology and Evolution
N2 - Most parasites and parasitoids are adapted to overcome defense mechanisms of their specific hosts and hence colonize a narrow range of host species. Accordingly, an increase in host functional or phylogenetic dissimilarity is expected to increase the species diversity of parasitoids. However, the local diversity of parasitoids may be driven by the accessibility and detectability of hosts, both increasing with increasing host abundance. Yet, the relative importance of these two mechanisms remains unclear. We parallelly reared communities of saproxylic beetle as potential hosts and associated parasitoid Hymenoptera from experimentally felled trees. The dissimilarity of beetle communities was inferred from distances in seven functional traits and from their evolutionary ancestry. We tested the effect of host abundance, species richness, functional, and phylogenetic dissimilarities on the abundance, species richness, and Shannon diversity of parasitoids. Our results showed an increase of abundance, species richness, and Shannon diversity of parasitoids with increasing beetle abundance. Additionally, abundance of parasitoids increased with increasing species richness of beetles. However, functional and phylogenetic dissimilarity showed no effect on the diversity of parasitoids. Our results suggest that the local diversity of parasitoids, of ephemeral and hidden resources like saproxylic beetles, is highest when resources are abundant and thereby detectable and accessible. Hence, in some cases, resources do not need to be diverse to promote parasitoid diversity.
KW - barcoding
KW - deadwood
KW - experiment
KW - host–parasitoid interaction
KW - natural enemy
KW - specialization
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-238892
VL - 11
IS - 11
SP - 6881
EP - 6888
ER -
TY - JOUR
A1 - Hock, Robert
A1 - Moormann, Antoon
A1 - Fischer, Dagmar
A1 - Scheer, Ulrich
T1 - Absence of somatic histone H1 in oocytes and preblastula embryos of Xenopus laevis
N2 - Available data on the occurrence and expression of somatic histone HI during oogenesis and early embryogenesis of Xenopus laevis are contradictory. In particular the reported presence of a large storage pool of histone HIA in oocytes is difficult to reconcile with the high transcriptional activity of all gene classes in this specific cell type. In the present study we have used polyclonal antibodies raised against somatic Xenopus histone HI (HIA and HIA/B) for combined immunoblotting experiments to quantitate HI pools and immunolocalization studies to visualize chromosome- bound HI. Both approaches failed to detect soluble or chromosomal histone HI in vitellogenic oocytes, eggs, and cleavage-stage embryos up to early blastula. In addition, chromatin assembled in Xenopus egg extract was also negative for histone HI as revealed by immunofluorescence microscopy. Lampbrush chromosomes not only lacked histone HI but also the previously identified histone HI-like B4 protein (Smith et al., 1988, Genes Dev. 2,1284-1295). In contrast, chromosomes of eggs and early embryos fluoresced brightly with anti-B4 antibodies. Our results lend further support to the view that histone HI expression is developmentally regulated during Xenopus oogenesis and embryogenesis similar to what is known from other species.
Y1 - 1993
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41350
ER -
TY - JOUR
A1 - Franke, Werner W.
A1 - Scheer, Ulrich
A1 - Trendelenburg, Michael F.
A1 - Spring, Herbert
A1 - Zentgraf, Hanswalter
T1 - Absence of nucleosomes in transcriptionally active chromatin
N2 - The ultrastructure of twO kinds of transcription ally active chromatin, the lampbrush chromosome loops and the nucleoli from amphibian oocytes and primary nuclei of the green alga Acetabularia, has been examined after manual isolation and dispersion in low salt media of slightly alkaline pH using various electron microscopic staining techniques (positive staining, metal shadowing, negative staining, preparation on positively charged films, etc.) and compared with the appearance of chromatin from various somatic cells (hen erythrocytes, rat hepatocytes, ClIltured murine sarcoma cells) prepared in parallel. While typical nucleosomes were revealed with all the techniques for chromatin from the latter three cell system, no nucleosomes were identified in either the lampbrush chromosome structures or the nucleolar chromatin. Nucleosomal arrays were absent not only in maximally fibril-covered matrix units but also in fibril-free regions between transcriptional complexes, including the apparent spacer intercepts between different transcriptional units. Moreover, comparisons of the length of the repeating units of rDNA in the transcribed state with those determined in the isolated rDNA and with the lengths of the first stable product of rDNA transcription, the pre-rRNA, demonstrated that the transcribed rDNA was not significantly shortened and/or condensed but rather extended in the transcriptional units. Distinct granules of about nucleosomal size which were sometimes found in apparent spacer regions as well as within matrix units of reduced fibril density were shown not to represent nucleosomes since their number per spacer unit was not inversely correlated with the length of the specific unit and also on the basis of their resistance to treatment with the detergent Sarkosyl NL-30. It is possible to structurally distinguish between transcriptionally active chromatin in which the DNA is extended in a non-nucleosomal form of chromatin and condensed, inactive chromatin within the typical nucleosomal package. The characteristic extended structure of transcriptionally active chromatin is found not only in the transcribed genes but also in non-transcribed regions within or between ("spacer") transcriptional units as well as in transcriptional units that are untranscribed amidst transcribed ones and/or have been inactivated for relatively short time. It is hypothesized that activation of transcription involves a transition from a nucleosomal to an extended chromatin organisation and that this structural transition is not specific for single "activated" genes but may involve larger chromatin regions, including adjacent untranscribed intercepts.
KW - Cytologie
KW - Chromatin structure
KW - nucleosomes
KW - transcription
KW - electron microscopy
Y1 - 1976
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40646
ER -
TY - JOUR
A1 - Rackevei, Antonia S.
A1 - Borges, Alyssa
A1 - Engstler, Markus
A1 - Dandekar, Thomas
A1 - Wolf, Matthias
T1 - About the analysis of 18S rDNA sequence data from trypanosomes in barcoding and phylogenetics: tracing a continuation error occurring in the literature
JF - Biology
N2 - The variable regions (V1–V9) of the 18S rDNA are routinely used in barcoding and phylogenetics. In handling these data for trypanosomes, we have noticed a misunderstanding that has apparently taken a life of its own in the literature over the years. In particular, in recent years, when studying the phylogenetic relationship of trypanosomes, the use of V7/V8 was systematically established. However, considering the current numbering system for all other organisms (including other Euglenozoa), V7/V8 was never used. In Maia da Silva et al. [Parasitology 2004, 129, 549–561], V7/V8 was promoted for the first time for trypanosome phylogenetics, and since then, more than 70 publications have replicated this nomenclature and even discussed the benefits of the use of this region in comparison to V4. However, the primers used to amplify the variable region of trypanosomes have actually amplified V4 (concerning the current 18S rDNA numbering system).
KW - RNA secondary structure
KW - variable regions
KW - V1–V9
KW - V4
KW - V7/V8
KW - Trypanosoma
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297562
SN - 2079-7737
VL - 11
IS - 11
ER -
TY - JOUR
A1 - Wu, Yu
A1 - Pons, Valérie
A1 - Goudet, Amélie
A1 - Panigai, Laetitia
A1 - Fischer, Annette
A1 - Herweg, Jo-Ana
A1 - Kali, Sabrina
A1 - Davey, Robert A.
A1 - Laporte, Jérôme
A1 - Bouclier, Céline
A1 - Yousfi, Rahima
A1 - Aubenque, Céline
A1 - Merer, Goulven
A1 - Gobbo, Emilie
A1 - Lopez, Roman
A1 - Gillet, Cynthia
A1 - Cojean, Sandrine
A1 - Popoff, Michel R.
A1 - Clayette, Pascal
A1 - Le Grand, Roger
A1 - Boulogne, Claire
A1 - Tordo, Noël
A1 - Lemichez, Emmanuel
A1 - Loiseau, Philippe M.
A1 - Rudel, Thomas
A1 - Sauvaire, Didier
A1 - Cintrat, Jean-Christophe
A1 - Gillet, Daniel
A1 - Barbier, Julien
T1 - ABMA, a small molecule that inhibits intracellular toxins and pathogens by interfering with late endosomal compartments
JF - Scientific Reports
N2 - Intracellular pathogenic microorganisms and toxins exploit host cell mechanisms to enter, exert their deleterious effects as well as hijack host nutrition for their development. A potential approach to treat multiple pathogen infections and that should not induce drug resistance is the use of small molecules that target host components. We identifed the compound 1-adamantyl (5-bromo-2-methoxybenzyl) amine (ABMA) from a cell-based high throughput screening for its capacity to protect human cells and mice against ricin toxin without toxicity. This compound efciently protects cells against various toxins and pathogens including viruses, intracellular bacteria and parasite. ABMA provokes Rab7-positive late endosomal compartment accumulation in mammalian cells without affecting other organelles (early endosomes, lysosomes, the Golgi apparatus, the endoplasmic reticulum or the nucleus). As the mechanism of action of ABMA is restricted to host-endosomal compartments, it reduces cell infection by pathogens that depend on this pathway to invade cells. ABMA may represent a novel class of broad-spectrum compounds with therapeutic potential against diverse severe infectious diseases.
KW - biology
KW - antimicrobials
KW - high-throughput screening
KW - infectious diseases
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173170
VL - 7
ER -
TY - JOUR
A1 - Schwartz, Faina
A1 - Neve, Rachel
A1 - Eisenman, Robert
A1 - Gessler, Manfred
A1 - Bruns, Gail
T1 - A WAGR region gene between PAX-6 and FSHB expressed in fetal brain
N2 - Developmental delay or mental retardation is a frequent component of multi-system anomaly syndromes associated with chromosomal deletions. Isolation of genes involved in the mental dysfunction in these disorders should define loci important in brain formation or function. We have identified a highly conserved locus in the distal part of 11 p 13 that is prominently expressed in fetal brain. Minimal expression is observed in a number of other fetal tissues. The gene maps distal to PAX-6 but proximal to the loci for brain-derived neurotrophic factor (BDNF) and the beta subunit of follicle stimulating hormone (FSHB), within a region previously implicated in the mental retardation component of some WAGR syndrome patients. Within fetal brain, the corresponding transcript is prominent in frontal, motor and primary visual cortex as weil as in the caudate-putamen. The characteristics of this gene, including the striking evolutionary conservation at the locus, suggest that the encoded protein may function in brain development.
KW - Biochemie
Y1 - 1994
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59125
ER -
TY - JOUR
A1 - Jahn, Daniel
A1 - Schramm, Sabine
A1 - Schnölzer, Martina
A1 - Heilmann, Clemens J.
A1 - de Koster, Chris G.
A1 - Schütz, Wolfgang
A1 - Benavente, Ricardo
A1 - Alsheimer, Manfred
T1 - A truncated lamin A in the Lmna\(^{−/−}\) mouse line: Implications for the understanding of laminopathies
JF - Nucleus
N2 - During recent years a number of severe clinical syndromes, collectively termed laminopathies, turned out to be caused by various, distinct mutations in the human LMNA gene. Arising from this, remarkable progress has been made to unravel the molecular pathophysiology underlying these disorders. A great benefit in this context was the generation of an A-type lamin deficient mouse line (Lmna\(^{−/−}\)) by Sullivan and others,1 which has become one of the most frequently used models in the field and provided profound insights to many different aspects of A-type lamin function. Here, we report the unexpected finding that these mice express a truncated Lmna gene product on both transcriptional and protein level. Combining different approaches including mass spectrometry, we precisely define this product as a C-terminally truncated lamin A mutant that lacks domains important for protein interactions and post-translational processing. Based on our findings we discuss implications for the interpretation of previous studies using Lmna\(^{−/−}\) mice and the concept of human laminopathies.
KW - nuclear organization
KW - A-type lamins
KW - LMNA mutations
KW - laminopathies
KW - nuclear envelope
KW - nuclear lamina
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127281
VL - 3
IS - 5
ER -
TY - JOUR
A1 - Riehl, R.
A1 - Schartl, Manfred
T1 - A Transmission Electron Microscopical and Freeze-Etch Study of Malignant-Melanoma in Fish
N2 - No abstract available
KW - Physiologische Chemie
Y1 - 1984
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61916
ER -
TY - JOUR
A1 - Lamatsch, Dunja K.
A1 - Adolfsson, Sofia
A1 - Senior, Alistair M.
A1 - Christiansen, Guntram
A1 - Pichler, Maria
A1 - Ozaki, Yuichi
A1 - Smeds, Linnea
A1 - Schartl, Manfred
A1 - Nakagawa, Shinichi
T1 - A transcriptome derived female-specific marker from the invasive Western mosquitofish (Gambusia affinis)
JF - PLoS ONE
N2 - Sex-specific markers are a prerequisite for understanding reproductive biology, genetic factors involved in sex differences, mechanisms of sex determination, and ultimately the evolution of sex chromosomes. The Western mosquitofish, Gambusia affinis, may be considered a model species for sex-chromosome evolution, as it displays female heterogamety (ZW/ZZ), and is also ecologically interesting as a worldwide invasive species. Here, de novo RNA-sequencing on the gonads of sexually mature G. affinis was used to identify contigs that were highly transcribed in females but not in males (i.e., transcripts with ovary-specific expression). Subsequently, 129 primer pairs spanning 79 contigs were tested by PCR to identify sex-specific transcripts. Of those primer pairs, one female-specific DNA marker was identified, Sanger sequenced and subsequently validated in 115 fish. Sequence analyses revealed a high similarity between the identified sex-specific marker and the 3' UTR of the aminomethyl transferase (amt) gene of the closely related platyfish (Xiphophorus maculatus). This is the first time that RNA-seq has been used to successfully characterize a sex-specific marker in a fish species in the absence of a genome map. Additionally, the identified sex-specific marker represents one of only a handful of such markers in fishes.
KW - sex chromosome evolution
KW - linkage map
KW - determination locus
KW - poeciliid fishes
KW - heterogamety
KW - Cynoglossus semilaevis
KW - determining genes
KW - Y chromosome
KW - sequence alignment
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144004
VL - 10
IS - 2
ER -
TY - JOUR
A1 - Vey, Johannes
A1 - Kapsner, Lorenz A.
A1 - Fuchs, Maximilian
A1 - Unberath, Philipp
A1 - Veronesi, Giulia
A1 - Kunz, Meik
T1 - A toolbox for functional analysis and the systematic identification of diagnostic and prognostic gene expression signatures combining meta-analysis and machine learning
JF - Cancers
N2 - The identification of biomarker signatures is important for cancer diagnosis and prognosis. However, the detection of clinical reliable signatures is influenced by limited data availability, which may restrict statistical power. Moreover, methods for integration of large sample cohorts and signature identification are limited. We present a step-by-step computational protocol for functional gene expression analysis and the identification of diagnostic and prognostic signatures by combining meta-analysis with machine learning and survival analysis. The novelty of the toolbox lies in its all-in-one functionality, generic design, and modularity. It is exemplified for lung cancer, including a comprehensive evaluation using different validation strategies. However, the protocol is not restricted to specific disease types and can therefore be used by a broad community. The accompanying R package vignette runs in ~1 h and describes the workflow in detail for use by researchers with limited bioinformatics training.
KW - bioinformatics tool
KW - R package
KW - machine learning
KW - meta-analysis
KW - biomarker signature
KW - gene expression analysis
KW - survival analysis
KW - functional analysis
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193240
SN - 2072-6694
VL - 11
IS - 10
ER -
TY - JOUR
A1 - Lasway, Julius V.
A1 - Kinabo, Neema R.
A1 - Mremi, Rudolf F.
A1 - Martin, Emanuel H.
A1 - Nyakunga, Oliver C.
A1 - Sanya, John J.
A1 - Rwegasira, Gration M.
A1 - Lesio, Nicephor
A1 - Gideon, Hulda
A1 - Pauly, Alain
A1 - Eardley, Connal
A1 - Peters, Marcell K.
A1 - Peterson, Andrew T.
A1 - Steffan-Dewenter, Ingolf
A1 - Njovu, Henry K.
T1 - A synopsis of the Bee occurrence data of northern Tanzania
JF - Biodiversity Data Journal
N2 - Background
Bees (Hymenoptera: Apoidea: Anthophila) are the most important group of pollinators with about 20,507 known species worldwide. Despite the critical role of bees in providing pollination services, studies aiming at understanding which species are present across disturbance gradients are scarce. Limited taxononomic information for the existing and unidentified bee species in Tanzania make their conservation haphazard. Here, we present a dataset of bee species records obtained from a survey in nothern Tanzania i.e. Kilimanjaro, Arusha and Manyara regions. Our findings serve as baseline data necessary for understanding the diversity and distribution of bees in the northern parts of the country, which is a critical step in devising robust conservation and monitoring strategies for their populations.
New information
In this paper, we present information on 45 bee species belonging to 20 genera and four families sampled using a combination of sweep-netting and pan trap methods. Most species (27, ~ 60%) belong to the family Halictidae followed by 16 species (35.5%) from the family Apidae. Megachilidae and Andrenidae were the least represented, each with only one species (2.2%). Additional species of Apidae and Megachilidae sampled during this survey are not yet published on Global Biodiversity Information Facility (GBIF), once they will be available on GBIF, they will be published in a subsequent paper. From a total of 953 occurrences, highest numbers were recorded in Kilimanjaro Region (n = 511), followed by Arusha (n = 410) and Manyara (n = 32), but this pattern reflects the sampling efforts of the research project rather than real bias in the distributions of bee species in northern Tanzania.
KW - agriculture
KW - bee pollinator
KW - distribution
KW - disturbance gradient
KW - grazing
KW - species diversity
KW - Tanzania
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265018
VL - 9
ER -
TY - JOUR
A1 - Ioakeimidis, Fotis
A1 - Ott, Christine
A1 - Kozjak-Pavlovic, Vera
A1 - Violitzi, Foteini
A1 - Rinotas, Vagelis
A1 - Makrinou, Eleni
A1 - Eliopoulos, Elias
A1 - Fasseas, Costas
A1 - Kollias, George
A1 - Douni, Eleni
T1 - A Splicing Mutation in the Novel Mitochondrial Protein DNAJC11 Causes Motor Neuron Pathology Associated with Cristae Disorganization, and Lymphoid Abnormalities in Mice
JF - PLOS ONE
N2 - Mitochondrial structure and function is emerging as a major contributor to neuromuscular disease, highlighting the need for the complete elucidation of the underlying molecular and pathophysiological mechanisms. Following a forward genetics approach with N-ethyl-N-nitrosourea (ENU)-mediated random mutagenesis, we identified a novel mouse model of autosomal recessive neuromuscular disease caused by a splice-site hypomorphic mutation in a novel gene of unknown function, DnaJC11. Recent findings have demonstrated that DNAJC11 protein co-immunoprecipitates with proteins of the mitochondrial contact site (MICOS) complex involved in the formation of mitochondrial cristae and cristae junctions. Homozygous mutant mice developed locomotion defects, muscle weakness, spasticity, limb tremor, leucopenia, thymic and splenic hypoplasia, general wasting and early lethality. Neuropathological analysis showed severe vacuolation of the motor neurons in the spinal cord, originating from dilatations of the endoplasmic reticulum and notably from mitochondria that had lost their proper inner membrane organization. The causal role of the identified mutation in DnaJC11 was verified in rescue experiments by overexpressing the human ortholog. The full length 63 kDa isoform of human DNAJC11 was shown to localize in the periphery of the mitochondrial outer membrane whereas putative additional isoforms displayed differential submitochondrial localization. Moreover, we showed that DNAJC11 is assembled in a high molecular weight complex, similarly to mitofilin and that downregulation of mitofilin or SAM50 affected the levels of DNAJC11 in HeLa cells. Our findings provide the first mouse mutant for a putative MICOS protein and establish a link between DNAJC11 and neuromuscular diseases.
KW - dominant optic atrophy
KW - amyotrophic-lateral-sclerosis
KW - nervous system
KW - membrane organization
KW - mitofilin
KW - data-bank
KW - model
KW - biogenesis
KW - morphology
KW - reveals
Y1 - 2014
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-115581
VL - 9
IS - 8
ER -
TY - JOUR
A1 - Vortkamp, A.
A1 - Thias, U.
A1 - Gessler, Manfred
A1 - Rosenkranz, W.
A1 - Kroisel, P. M.
A1 - Tommerup, N.
A1 - Kruger, G.
A1 - Gotz, J.
A1 - Pelz, L.
A1 - Grzeschik, Karl-Heinz
T1 - A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p
N2 - No abstract available
KW - Biochemie
Y1 - 1991
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59217
ER -
TY - JOUR
A1 - Eckhardt, Manon
A1 - Anders, Maria
A1 - Muranyi, Walter
A1 - Heilemann, Mike
A1 - Krijnse-Locker, Jacomine
A1 - Müller, Barbara
T1 - A SNAP-Tagged Derivative of HIV-1-A Versatile Tool to Study Virus-Cell Interactions
JF - PLoS ONE
N2 - Fluorescently labeled human immunodeficiency virus (HIV) derivatives, combined with the use of advanced fluorescence microscopy techniques, allow the direct visualization of dynamic events and individual steps in the viral life cycle. HIV proteins tagged with fluorescent proteins (FPs) have been successfully used for live-cell imaging analyses of HIV-cell interactions. However, FPs display limitations with respect to their physicochemical properties, and their maturation kinetics. Furthermore, several independent FP-tagged constructs have to be cloned and characterized in order to obtain spectral variations suitable for multi-color imaging setups. In contrast, the so-called SNAP-tag represents a genetically encoded non-fluorescent tag which mediates specific covalent coupling to fluorescent substrate molecules in a self-labeling reaction. Fusion of the SNAP-tag to the protein of interest allows specific labeling of the fusion protein with a variety of synthetic dyes, thereby offering enhanced flexibility for fluorescence imaging approaches. Here we describe the construction and characterization of the HIV derivative HIV(SNAP), which carries the SNAP-tag as an additional domain within the viral structural polyprotein Gag. Introduction of the tag close to the C-terminus of the matrix domain of Gag did not interfere with particle assembly, release or proteolytic virus maturation. The modified virions were infectious and could be propagated in tissue culture, albeit with reduced replication capacity. Insertion of the SNAP domain within Gag allowed specific staining of the viral polyprotein in the context of virus producing cells using a SNAP reactive dye as well as the visualization of individual virions and viral budding sites by stochastic optical reconstruction microscopy. Thus, HIV(SNAP) represents a versatile tool which expands the possibilities for the analysis of HIV-cell interactions using live cell imaging and sub-diffraction fluorescence microscopy.
KW - Human-immunodeficiency-virus
KW - Fusion proteins
KW - Live cells
KW - Fluorescence microscopy
KW - Stimulated-emission
KW - Plasma-membrane
KW - Living cells
KW - Real-time
KW - TYPE-1
KW - GAG
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133534
VL - 6
IS - 7
ER -
TY - JOUR
A1 - Xu, Li
A1 - He, Jianzheng
A1 - Kaiser, Andrea
A1 - Gräber, Nikolas
A1 - Schläger, Laura
A1 - Ritze, Yvonne
A1 - Scholz, Henrike
T1 - A Single Pair of Serotonergic Neurons Counteracts Serotonergic Inhibition of Ethanol Attraction in Drosophila
JF - PLoS ONE
N2 - Attraction to ethanol is common in both flies and humans, but the neuromodulatory mechanisms underlying this innate attraction are not well understood. Here, we dissect the function of the key regulator of serotonin signaling—the serotonin transporter–in innate olfactory attraction to ethanol in Drosophila melanogaster. We generated a mutated version of the serotonin transporter that prolongs serotonin signaling in the synaptic cleft and is targeted via the Gal4 system to different sets of serotonergic neurons. We identified four serotonergic neurons that inhibit the olfactory attraction to ethanol and two additional neurons that counteract this inhibition by strengthening olfactory information. Our results reveal that compensation can occur on the circuit level and that serotonin has a bidirectional function in modulating the innate attraction to ethanol. Given the evolutionarily conserved nature of the serotonin transporter and serotonin, the bidirectional serotonergic mechanisms delineate a basic principle for how random behavior is switched into targeted approach behavior.
KW - attraction
KW - ethanol
KW - Drosophila melanogaster
KW - serotonin transporter
Y1 - 2016
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166762
VL - 11
IS - 12
ER -
TY - JOUR
A1 - Katja, Schulze
A1 - López, Diana A.
A1 - Tillich, Ulrich M.
A1 - Frohme, Marcus
T1 - A simple viability analysis for unicellular cyanobacteria using a new autofluorescence assay, automated microscopy, and ImageJ
JF - BMC Biotechnology
N2 - Background
Currently established methods to identify viable and non-viable cells of cyanobacteria are either time-consuming (eg. plating) or preparation-intensive (eg. fluorescent staining). In this paper we present a new and fast viability assay for unicellular cyanobacteria, which uses red chlorophyll fluorescence and an unspecific green autofluorescence for the differentiation of viable and non-viable cells without the need of sample preparation.
Results
The viability assay for unicellular cyanobacteria using red and green autofluorescence was established and validated for the model organism Synechocystis sp. PCC 6803. Both autofluorescence signals could be observed simultaneously allowing a direct classification of viable and non-viable cells. The results were confirmed by plating/colony count, absorption spectra and chlorophyll measurements. The use of an automated fluorescence microscope and a novel ImageJ based image analysis plugin allow a semi-automated analysis.
Conclusions
The new method simplifies the process of viability analysis and allows a quick and accurate analysis. Furthermore results indicate that a combination of the new assay with absorption spectra or chlorophyll concentration measurements allows the estimation of the vitality of cells.
KW - variability analysis
KW - unicellular cyanobacteria
KW - autofluorescence
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-137735
VL - 11
IS - 118
ER -
TY - JOUR
A1 - Schartl, Manfred
T1 - A sex chromosomal restriction-fragment-length marker linked to melanoma-determining Tu loci in Xiphophorus
N2 - No abstract available
KW - Physiologische Chemie
Y1 - 1988
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61842
ER -
TY - JOUR
A1 - Solger, Franziska
A1 - Kunz, Tobias C.
A1 - Fink, Julian
A1 - Paprotka, Kerstin
A1 - Pfister, Pauline
A1 - Hagen, Franziska
A1 - Schumacher, Fabian
A1 - Kleuser, Burkhard
A1 - Seibel, Jürgen
A1 - Rudel, Thomas
T1 - A Role of Sphingosine in the Intracellular Survival of Neisseria gonorrhoeae
JF - Frontiers in Cellular and Infection Microbiology
N2 - Obligate human pathogenic Neisseria gonorrhoeae are the second most frequent bacterial cause of sexually transmitted diseases. These bacteria invade different mucosal tissues and occasionally disseminate into the bloodstream. Invasion into epithelial cells requires the activation of host cell receptors by the formation of ceramide-rich platforms. Here, we investigated the role of sphingosine in the invasion and intracellular survival of gonococci. Sphingosine exhibited an anti-gonococcal activity in vitro. We used specific sphingosine analogs and click chemistry to visualize sphingosine in infected cells. Sphingosine localized to the membrane of intracellular gonococci. Inhibitor studies and the application of a sphingosine derivative indicated that increased sphingosine levels reduced the intracellular survival of gonococci. We demonstrate here, that sphingosine can target intracellular bacteria and may therefore exert a direct bactericidal effect inside cells.
KW - sphingosine
KW - sphingolipids
KW - sphingosine kinases
KW - invasion
KW - survival
KW - click chemistry
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-204111
SN - 2235-2988
VL - 10
ER -
TY - JOUR
A1 - Zimmermann, Henriette
A1 - Subota, Ines
A1 - Batram, Christopher
A1 - Kramer, Susanne
A1 - Janzen, Christian J.
A1 - Jones, Nicola G.
A1 - Engstler, Markus
T1 - A quorum sensing-independent path to stumpy development in Trypanosoma brucei
JF - PLoS Pathogens
N2 - For persistent infections of the mammalian host, African trypanosomes limit their population size by quorum sensing of the parasite-excreted stumpy induction factor (SIF), which induces development to the tsetse-infective stumpy stage. We found that besides this cell density-dependent mechanism, there exists a second path to the stumpy stage that is linked to antigenic variation, the main instrument of parasite virulence. The expression of a second variant surface glycoprotein (VSG) leads to transcriptional attenuation of the VSG expression site (ES) and immediate development to tsetse fly infective stumpy parasites. This path is independent of SIF and solely controlled by the transcriptional status of the ES. In pleomorphic trypanosomes varying degrees of ES-attenuation result in phenotypic plasticity. While full ES-attenuation causes irreversible stumpy development, milder attenuation may open a time window for rescuing an unsuccessful antigenic switch, a scenario that so far has not been considered as important for parasite survival.
KW - Trypanosoma
KW - hyperexpression techniques
KW - parasitic cell cycles
KW - cloning
KW - cell cycle and cell division
KW - cell differentiation
KW - tetracyclines
KW - parasitic diseases
Y1 - 2017
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158230
VL - 13
IS - 4
ER -
TY - JOUR
A1 - Weiße, Sebastian
A1 - Heddergott, Niko
A1 - Heydt, Matthias
A1 - Pflästerer, Daniel
A1 - Maier, Timo
A1 - Haraszti, Tamas
A1 - Grunze, Michael
A1 - Engstler, Markus
A1 - Rosenhahn, Axel
T1 - A Quantitative 3D Motility Analysis of Trypanosoma brucei by Use of Digital In-line Holographic Microscopy
JF - PLoS One
N2 - We present a quantitative 3D analysis of the motility of the blood parasite Trypanosoma brucei. Digital in-line holographic microscopy has been used to track single cells with high temporal and spatial accuracy to obtain quantitative data on their behavior. Comparing bloodstream form and insect form trypanosomes as well as mutant and wildtype cells under varying external conditions we were able to derive a general two-state-run-and-tumble-model for trypanosome motility. Differences in the motility of distinct strains indicate that adaption of the trypanosomes to their natural environments involves a change in their mode of swimming.
KW - african trypanosomes
KW - actin cortex
KW - flagellum
KW - tracking
KW - surface
KW - models
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130666
VL - 7
IS - 5
ER -
TY - JOUR
A1 - Däullary, Thomas
A1 - Imdahl, Fabian
A1 - Dietrich, Oliver
A1 - Hepp, Laura
A1 - Krammer, Tobias
A1 - Fey, Christina
A1 - Neuhaus, Winfried
A1 - Metzger, Marco
A1 - Vogel, Jörg
A1 - Westermann, Alexander J.
A1 - Saliba, Antoine-Emmanuel
A1 - Zdzieblo, Daniela
T1 - A primary cell-based in vitro model of the human small intestine reveals host olfactomedin 4 induction in response to Salmonella Typhimurium infection
JF - Gut Microbes
N2 - Infection research largely relies on classical cell culture or mouse models. Despite having delivered invaluable insights into host-pathogen interactions, both have limitations in translating mechanistic principles to human pathologies. Alternatives can be derived from modern Tissue Engineering approaches, allowing the reconstruction of functional tissue models in vitro. Here, we combined a biological extracellular matrix with primary tissue-derived enteroids to establish an in vitro model of the human small intestinal epithelium exhibiting in vivo-like characteristics. Using the foodborne pathogen Salmonella enterica serovar Typhimurium, we demonstrated the applicability of our model to enteric infection research in the human context. Infection assays coupled to spatio-temporal readouts recapitulated the established key steps of epithelial infection by this pathogen in our model. Besides, we detected the upregulation of olfactomedin 4 in infected cells, a hitherto unrecognized aspect of the host response to Salmonella infection. Together, this primary human small intestinal tissue model fills the gap between simplistic cell culture and animal models of infection, and shall prove valuable in uncovering human-specific features of host-pathogen interplay.
KW - intestinal enteroids
KW - biological scaffold
KW - Salmonella Typhimurium
KW - OLFM4
KW - NOTCH
KW - filamentous Salmonella Typhimurium
KW - bacterial migration
KW - bacterial virulence
KW - 3D tissue model
KW - olfactomedin 4
KW - infection
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350451
VL - 15
IS - 1
ER -
TY - JOUR
A1 - Gessler, Manfred
A1 - Bruns, G. A. P.
T1 - A physical map around the WAGR complex on the short arm of chromosome 11
N2 - A long-range restriction map of part of the short arm of ehromosome 11 including the WAGR region has been constructed using pulsed-field gel electrophoresis and a number of infrequently cutting restriction enzymes. A total of 15.4 Mbp has been mapped in detall, extending from proximal 11p14 to the distal part of 11p12. The map localizes 35 different DNA probes and reveals at least nine areas with features eharaeteristle of BTF islands, some of which may be candidates for the different loci underlying the phenotype of the WAGR syndrome. This map will furthermore allow screening of DNA from individuals with WAGR-related phenotypes and from Wilms tumors for associated chromosomal rearrangements.
KW - Biochemie
Y1 - 1989
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59246
ER -
TY - JOUR
A1 - Franke, Werner W.
A1 - Kleinschmidt, Jürgen A.
A1 - Spring, Herbert
A1 - Krohne, Georg
A1 - Grund, Christine
A1 - Trendelenburg, Michael F.
A1 - Stöhr, Michael
A1 - Scheer, Ulrich
T1 - A nucleolar skeleton of protein filaments demonstrated in amplified nucleoli of Xenopus laevis
N2 - The amplified, extrachromosomal nucleoli of Xenopus oocytes contain a meshwork of -4-nm-thick filaments, which are densely coiled into higher-order fibrils of diameter 30-40 nm and are resistant to treatment with high- and low-salt concentrations, nucleases (DNase I, pancreatic RNase, micrococcal nuclease), sulfhydryl agents, and various nonionic detergents. This filamentous "skeleton" has been prepared from manually isolated nuclear contents and nucleoli as weil as from nucleoli isolated by fluorescence-activated particle sorting. The nucleolar skeletons are observed in light and electron microscopy and are characterized by ravels of filaments that are especially densely packed in the nucleolar cortex. DNA as weil as RNA are not constituents of this structure, and precursors to ribosomal RNAs are completely removed from the extraction-resistant filaments by treatment with high-salt buffer or RN ase. Fractions of isolated nucleolar skeletons show specific enrichment of an acidic major protein of 145,000 mol wt and an apparent pi value of -6.15, accompanied in some preparations by various amounts of minor proteins. The demonstration of this skeletal structure in "free" extrachromosomal nucleoli excludes the problem of contaminations by nonnucleolar material such as perinucleolar heterochromatin normally encountered in studies of nucleoli from somatic cells. It is suggested that this insoluble protein filament complex forms a skeleton specific to the nucleolus proper that is different from other extraction-resistant components of the nucleus such as matrix and lamina and is involved in the spatial organization of the nucleolar chromatin and its transcriptional products. In studies of the organization of the interphase nucleus, considerable progress has been made in the elucidation of the arrangement of chromatin components and transcriptional products. However, relatively little is known about the composition and function of another category of nuclear structures, the nonnucleoproteinaceous architectural components that are insoluble in solutions of low and high ionic strength, despite numerous studies dedicated to this problem. Such structures include (a) the nuclear envelope and its pore complexes (I, 15, 18, 23, 37, 41), (b) a peripheral layer of insoluble protein ("lamina"; I, 15, 22, 23, 59), (e) certain skeletal proteins related to the chromosome "scaffold" described by Laemmli and coworkers (see references 2 and 3), and (d) ill-defined tangles of fibrillar structures of the nuclear interior that are collectively described as residual "matrix" (6, 21 ; for reviews, see references THE JOURNAL OF CEll BrOlOGY . VOlUME 90 AUGUST 1981 289-299 © The RockefeIler University Press · 0021 -9525/ 81 / 08/ 0289/ 11 $1 .00 4 and 12). The latter, preparatively
Y1 - 1981
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33130
ER -
TY - JOUR
A1 - Scharmann, Mathias
A1 - Thornham, Daniel G.
A1 - Grafe, T. Ulmar
A1 - Federle, Walter
T1 - A Novel Type of Nutritional Ant-Plant Interaction: Ant Partners of Carnivorous Pitcher Plants Prevent Nutrient Export by Dipteran Pitcher Infauna
JF - PLoS ONE
N2 - Many plants combat herbivore and pathogen attack indirectly by attracting predators of their herbivores. Here we describe a novel type of insect-plant interaction where a carnivorous plant uses such an indirect defence to prevent nutrient loss to kleptoparasites. The ant Camponotus schmitzi is an obligate inhabitant of the carnivorous pitcher plant Nepenthes bicalcarata in Borneo. It has recently been suggested that this ant-plant interaction is a nutritional mutualism, but the detailed mechanisms and the origin of the ant-derived nutrient supply have remained unexplained. We confirm that N. bicalcarata host plant leaves naturally have an elevated \(^{15}N/^{14}N\) stable isotope abundance ratio (\(\delta ^{15}N\)) when colonised by C. schmitzi. This indicates that a higher proportion of the plants' nitrogen is insect-derived when C. schmitzi ants are present (ca. 100%, vs. 77% in uncolonised plants) and that more nitrogen is available to them. We demonstrated direct flux of nutrients from the ants to the host plant in a \(^{15}N\) pulse-chase experiment. As C. schmitzi ants only feed on nectar and pitcher contents of their host, the elevated foliar \(\delta ^{15}N\) cannot be explained by classic ant-feeding (myrmecotrophy) but must originate from a higher efficiency of the pitcher traps. We discovered that C. schmitzi ants not only increase the pitchers' capture efficiency by keeping the pitchers' trapping surfaces clean, but they also reduce nutrient loss from the pitchers by predating dipteran pitcher inhabitants (infauna). Consequently, nutrients the pitchers would have otherwise lost via emerging flies become available as ant colony waste. The plants' prey is therefore conserved by the ants. The interaction between C. schmitzi, N. bicalcarata and dipteran pitcher infauna represents a new type of mutualism where animals mitigate the damage by nutrient thieves to a plant.
KW - community
KW - alternative trapping strategies
KW - leaf-litter utilization
KW - nepenthes bicalcarata
KW - camponotus schmitzi
KW - food web
KW - epiphytic fern
KW - nitrogen
KW - prey
KW - rafflesiana
Y1 - 2013
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130952
VL - 8
IS - 5
ER -
TY - JOUR
A1 - Scheer, Ulrich
T1 - A novel type of chromatin organization in lampbrush chromosomes of Pleurodeles waltlii: visualization of clusters of tandemly repeated, very short transcriptional units
N2 - A novel chromatin configuration is described in lampbrush chromosomes of Pleurodeles waltlii oocytes which is different from transcriptionally inactive chromatin as weil as from the various forms of transcribed chromatin hitherto described. This novel type of chromatin is not arranged in Christmas tree-Iike configurations of densely packed lateral ribonucleoprotein (RNP) fibriIs but is characterized by a periodic alternating pattern of thick and thin regions which occur in clusters 01 some 10,000 repeats. Each thickened unit with an average length of 45 nm contains two c10sely spaced particles, the putative RNA polymerases, and each thickened unit is separated from the next one by a beaded chromatin spacer with a length of about 80 nm. This chromatin spacer contains on average two particles of approximately 14 nm in diameter, assumed to be nucleosomes. The thickened regions are interpreted to represent short transcriptional units containing approximately 130 base pairs of DNA which are separated from each other by nontranscribed spacers of 240-400 base pairs of DNA. The possibility is discussed that these transcriptional units represent 5S rRNA or tRNA genes.
KW - Lampbrush chromosomes
KW - Amphibian oocytes
KW - Transcription units
KW - Electron microscopy
Y1 - 1982
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41087
ER -
TY - JOUR
A1 - Vellmer, Tim
A1 - Hartleb, Laura
A1 - Fradera Sola, Albert
A1 - Kramer, Susanne
A1 - Meyer-Natus, Elisabeth
A1 - Butter, Falk
A1 - Janzen, Christian J.
T1 - A novel SNF2 ATPase complex in Trypanosoma brucei with a role in H2A.Z-mediated chromatin remodelling
JF - PLoS Pathogens
N2 - A cascade of histone acetylation events with subsequent incorporation of a histone H2A variant plays an essential part in transcription regulation in various model organisms. A key player in this cascade is the chromatin remodelling complex SWR1, which replaces the canonical histone H2A with its variant H2A.Z. Transcriptional regulation of polycistronic transcription units in the unicellular parasite Trypanosoma brucei has been shown to be highly dependent on acetylation of H2A.Z, which is mediated by the histone-acetyltransferase HAT2. The chromatin remodelling complex which mediates H2A.Z incorporation is not known and an SWR1 orthologue in trypanosomes has not yet been reported. In this study, we identified and characterised an SWR1-like remodeller complex in T. brucei that is responsible for Pol II-dependent transcriptional regulation. Bioinformatic analysis of potential SNF2 DEAD/Box helicases, the key component of SWR1 complexes, identified a 1211 amino acids-long protein that exhibits key structural characteristics of the SWR1 subfamily. Systematic protein-protein interaction analysis revealed the existence of a novel complex exhibiting key features of an SWR1-like chromatin remodeller. RNAi-mediated depletion of the ATPase subunit of this complex resulted in a significant reduction of H2A.Z incorporation at transcription start sites and a subsequent decrease of steady-state mRNA levels. Furthermore, depletion of SWR1 and RNA-polymerase II (Pol II) caused massive chromatin condensation. The potential function of several proteins associated with the SWR1-like complex and with HAT2, the key factor of H2A.Z incorporation, is discussed.
KW - Trypanosoma
KW - chromatin
KW - histones
KW - RNA interference
KW - Trypanosoma brucei gambiense
KW - luciferase
KW - transcriptional control
KW - nucleosomes
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-301372
VL - 18
IS - 6
ER -
TY - JOUR
A1 - Schramm, Sabine
A1 - Fraune, Johanna
A1 - Naumann, Ronald
A1 - Hernandez-Hernandez, Abrahan
A1 - Höög, Christer
A1 - Cooke, Howard J.
A1 - Alsheimer, Manfred
A1 - Benavente, Ricardo
T1 - A Novel Mouse Synaptonemal Complex Protein Is Essential for Loading of Central Element Proteins, Recombination, and Fertility
N2 - The synaptonemal complex (SC) is a proteinaceous, meiosis-specific structure that is highly conserved in evolution. During meiosis, the SC mediates synapsis of homologous chromosomes. It is essential for proper recombination and segregation of homologous chromosomes, and therefore for genome haploidization. Mutations in human SC genes can cause infertility. In order to gain a better understanding of the process of SC assembly in a model system that would be relevant for humans, we are investigating meiosis in mice. Here, we report on a newly identified component of the murine SC, which we named SYCE3. SYCE3 is strongly conserved among mammals and localizes to the central element (CE) of the SC. By generating a Syce3 knockout mouse, we found that SYCE3 is required for fertility in both sexes. Loss of SYCE3 blocks synapsis initiation and results in meiotic arrest. In the absence of SYCE3, initiation of meiotic recombination appears to be normal, but its progression is severely impaired resulting in complete absence of MLH1 foci, which are presumed markers of crossovers in wild-type meiocytes. In the process of SC assembly, SYCE3 is required downstream of transverse filament protein SYCP1, but upstream of the other previously described CE–specific proteins. We conclude that SYCE3 enables chromosome loading of the other CE–specific proteins, which in turn would promote synapsis between homologous chromosomes.
KW - Maus
KW - Genetik
KW - Cytologie
Y1 - 2011
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68895
ER -
TY - JOUR
A1 - Schartl, Manfred
A1 - Schröder, Johannes Horst
T1 - A new species of the genus Xiphophorus Heckel 1848, endemic to northern Coahuila, Mexico (Pisces: Poeciliidae)
N2 - Xiphophorus meyeri n. sp. is described as an endemic to Muzquiz, Coahuila, Mexico. It appears to be the northernmost species of the genus. The new species is related to X. couchianus and X. gordoni, but differs morphologically from those by dorsal fin ray number, by the expression of some gonopodial features and most markedly by the appearance of macromelanophores or tr-melanophores.
KW - Schwertkräpfling
KW - Coahuila
Y1 - 1987
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87117
ER -
TY - JOUR
A1 - Walter, Thomas
A1 - Degen, Jacqueline
A1 - Pfeiffer, Keram
A1 - Stöckl, Anna
A1 - Montenegro, Sergio
A1 - Degen, Tobias
T1 - A new innovative real-time tracking method for flying insects applicable under natural conditions
JF - BMC Zoology
N2 - Background
Sixty percent of all species are insects, yet despite global efforts to monitor animal movement patterns, insects are continuously underrepresented. This striking difference between species richness and the number of species monitored is not due to a lack of interest but rather to the lack of technical solutions. Often the accuracy and speed of established tracking methods is not high enough to record behavior and react to it experimentally in real-time, which applies in particular to small flying animals.
Results
Our new method of real-time tracking relates to frequencies of solar radiation which are almost completely absorbed by traveling through the atmosphere. For tracking, photoluminescent tags with a peak emission (1400 nm), which lays in such a region of strong absorption through the atmosphere, were attached to the animals. The photoluminescent properties of passivated lead sulphide quantum dots were responsible for the emission of light by the tags and provide a superb signal-to noise ratio. We developed prototype markers with a weight of 12.5 mg and a diameter of 5 mm. Furthermore, we developed a short wave infrared detection system which can record and determine the position of an animal in a heterogeneous environment with a delay smaller than 10 ms. With this method we were able to track tagged bumblebees as well as hawk moths in a flight arena that was placed outside on a natural meadow.
Conclusion
Our new method eliminates the necessity of a constant or predictable environment for many experimental setups. Furthermore, we postulate that the developed matrix-detector mounted to a multicopter will enable tracking of small flying insects, over medium range distances (>1000m) in the near future because: a) the matrix-detector equipped with an 70 mm interchangeable lens weighs less than 380 g, b) it evaluates the position of an animal in real-time and c) it can directly control and communicate with electronic devices.
KW - natural environment
KW - insect tracking
KW - real-time
KW - movement ecology
KW - heterogeneous background
Y1 - 2021
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265716
VL - 6
ER -