TY - JOUR A1 - Fazeli, Gholamreza A1 - Beer, Katharina B. A1 - Geisenhof, Michaela A1 - Tröger, Sarah A1 - König, Julia A1 - Müller-Reichert, Thomas A1 - Wehman, Ann M. T1 - Loss of the Major Phosphatidylserine or Phosphatidylethanolamine Flippases Differentially Affect Phagocytosis JF - Frontiers in Cell and Developmental Biology N2 - The lipids phosphatidylserine (PtdSer) and phosphatidylethanolamine (PtdEth) are normally asymmetrically localized to the cytosolic face of membrane bilayers, but can both be externalized during diverse biological processes, including cell division, cell fusion, and cell death. Externalized lipids in the plasma membrane are recognized by lipid-binding proteins to regulate the clearance of cell corpses and other cell debris. However, it is unclear whether PtdSer and PtdEth contribute in similar or distinct ways to these processes. We discovered that disruption of the lipid flippases that maintain PtdSer or PtdEth asymmetry in the plasma membrane have opposite effects on phagocytosis in Caenorhabditis elegans embryos. Constitutive PtdSer externalization caused by disruption of the major PtdSer flippase TAT-1 led to increased phagocytosis of cell debris, sometimes leading to two cells engulfing the same debris. In contrast, PtdEth externalization caused by depletion of the major PtdEth flippase TAT-5 or its activator PAD-1 disrupted phagocytosis. These data suggest that PtdSer and PtdEth externalization have opposite effects on phagocytosis. Furthermore, externalizing PtdEth is associated with increased extracellular vesicle release, and we present evidence that the extent of extracellular vesicle accumulation correlates with the extent of phagocytic defects. Thus, a general loss of lipid asymmetry can have opposing impacts through different lipid subtypes simultaneously exerting disparate effects. KW - phagocytosis KW - lipid asymmetry KW - flippase KW - phosphatidylserine KW - phosphatidylethanolamine KW - extracellular vesicle Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208771 SN - 2296-634X VL - 8 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 - Krebs, Markus A1 - Solimando, Antonio Giovanni A1 - Kalogirou, Charis A1 - Marquardt, André A1 - Frank, Torsten A1 - Sokolakis, Ioannis A1 - Hatzichristodoulou, Georgios A1 - Kneitz, Susanne A1 - Bargou, Ralf A1 - Kübler, Hubert A1 - Schilling, Bastian A1 - Spahn, Martin A1 - Kneitz, Burkhard T1 - miR-221-3p Regulates VEGFR2 Expression in High-Risk Prostate Cancer and Represents an Escape Mechanism from Sunitinib In Vitro JF - Journal of Clinical Medicine N2 - Downregulation of miR-221-3p expression in prostate cancer (PCa) predicted overall and cancer-specific survival of high-risk PCa patients. Apart from PCa, miR-221-3p expression levels predicted a response to tyrosine kinase inhibitors (TKI) in clear cell renal cell carcinoma (ccRCC) patients. Since this role of miR-221-3p was explained with a specific targeting of VEGFR2, we examined whether miR-221-3p regulated VEGFR2 in PCa. First, we confirmed VEGFR2/KDR as a target gene of miR-221-3p in PCa cells by applying Luciferase reporter assays and Western blotting experiments. Although VEGFR2 was mainly downregulated in the PCa cohort of the TCGA (The Cancer Genome Atlas) database, VEGFR2 was upregulated in our high-risk PCa cohort (n = 142) and predicted clinical progression. In vitro miR-221-3p acted as an escape mechanism from TKI in PC3 cells, as displayed by proliferation and apoptosis assays. Moreover, we confirmed that Sunitinib induced an interferon-related gene signature in PC3 cells by analyzing external microarray data and by demonstrating a significant upregulation of miR-221-3p/miR-222-3p after Sunitinib exposure. Our findings bear a clinical perspective for high-risk PCa patients with low miR-221-3p levels since this could predict a favorable TKI response. Apart from this therapeutic niche, we identified a partially oncogenic function of miR-221-3p as an escape mechanism from VEGFR2 inhibition. KW - microRNA-221 KW - high-risk Prostate Cancer KW - angiogenesis KW - Sunitinib KW - Tyrosine kinase inhibition Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203168 SN - 2077-0383 VL - 9 IS - 3 ER - TY - JOUR A1 - Götz, Ralph A1 - Panzer, Sabine A1 - Trinks, Nora A1 - Eilts, Janna A1 - Wagener, Johannes A1 - Turrà, David A1 - Di Pietro, Antonio A1 - Sauer, Markus A1 - Terpitz, Ulrich T1 - Expansion Microscopy for Cell Biology Analysis in Fungi JF - Frontiers in Microbiology N2 - Super-resolution microscopy has evolved as a powerful method for subdiffraction-resolution fluorescence imaging of cells and cellular organelles, but requires sophisticated and expensive installations. Expansion microscopy (ExM), which is based on the physical expansion of the cellular structure of interest, provides a cheap alternative to bypass the diffraction limit and enable super-resolution imaging on a conventional fluorescence microscope. While ExM has shown impressive results for the magnified visualization of proteins and RNAs in cells and tissues, it has not yet been applied in fungi, mainly due to their complex cell wall. Here we developed a method that enables reliable isotropic expansion of ascomycetes and basidiomycetes upon treatment with cell wall degrading enzymes. Confocal laser scanning microscopy (CLSM) and structured illumination microscopy (SIM) images of 4.5-fold expanded sporidia of Ustilago maydis expressing fluorescent fungal rhodopsins and hyphae of Fusarium oxysporum or Aspergillus fumigatus expressing either histone H1-mCherry together with Lifeact-sGFP or mRFP targeted to mitochondria, revealed details of subcellular structures with an estimated spatial resolution of around 30 nm. ExM is thus well suited for cell biology studies in fungi on conventional fluorescence microscopes. KW - Expansion microscopy KW - fluorescence microscopy KW - fungi KW - sporidia KW - hyphae Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202569 SN - 1664-302X VL - 11 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 - Cosarinsky, Marcela I. A1 - Römer, Daniela A1 - Roces, Flavio T1 - Nest Turrets of Acromyrmex Grass-Cutting Ants: Micromorphology Reveals Building Techniques and Construction Dynamics JF - Insects N2 - Acromyrmex fracticornis grass-cutting ants construct conspicuous chimney-shaped nest turrets made of intermeshed grass fragments. We asked whether turrets are constructed by merely piling up nearby materials around the entrance, or whether ants incorporate different materials as the turret develops. By removing the original nest turrets and following their rebuilding process over three consecutive days, age-dependent changes in wall morphology and inner lining fabrics were characterized. Micromorphological descriptions based on thin sections of turret walls revealed the building behaviors involved. Ants started by collecting nearby twigs and dry grass fragments that are piled up around the nest entrance. Several large fragments held the structure like beams. As a net-like structure grew, soil pellets were placed in between the intermeshed plant fragments from the turret base to the top, reinforcing the structure. Concomitantly, the turret inner wall was lined with soil pellets, starting from the base. Therefore, the consolidation of the turret occurred both over time and from its base upwards. It is argued that nest turrets do not simply arise by the arbitrary deposition of nearby materials, and that workers selectively incorporate large materials at the beginning, and respond to the developing structure by reinforcing the intermeshed plant fragments over time. KW - building behavior KW - Acromyrmex fracticornis KW - leaf-cutting ants KW - collective pattern KW - architecture KW - self-organization KW - microstructure KW - material composition KW - thin sections Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200680 SN - 2075-4450 VL - 11 IS - 2 ER - TY - JOUR A1 - Biscotti, Maria Assunta A1 - Carducci, Federica A1 - Barucca, Marco A1 - Gerdol, Marco A1 - Pallavicini, Alberto A1 - Schartl, Manfred A1 - Canapa, Adriana A1 - Contar Adolfi, Mateus T1 - The transcriptome of the newt Cynops orientalis provides new insights into evolution and function of sexual gene networks in sarcopterygians JF - Scientific Reports N2 - Amphibians evolved in the Devonian period about 400 Mya and represent a transition step in tetrapod evolution. Among amphibians, high-throughput sequencing data are very limited for Caudata, due to their largest genome sizes among terrestrial vertebrates. In this paper we present the transcriptome from the fire bellied newt Cynops orientalis. Data here presented display a high level of completeness, comparable to the fully sequenced genomes available from other amphibians. Moreover, this work focused on genes involved in gametogenesis and sexual development. Surprisingly, the gsdf gene was identified for the first time in a tetrapod species, so far known only from bony fish and basal sarcopterygians. Our analysis failed to isolate fgf24 and foxl3, supporting the possible loss of both genes in the common ancestor of Rhipidistians. In Cynops, the expression analysis of genes described to be sex-related in vertebrates singled out an expected functional role for some genes, while others displayed an unforeseen behavior, confirming the high variability of the sex-related pathway in vertebrates. KW - developmental biology KW - evolution Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227326 VL - 10 ER - TY - JOUR A1 - Doll, Julia A1 - Vona, Barbara A1 - Schnapp, Linda A1 - Rüschendorf, Franz A1 - Khan, Imran A1 - Khan, Saadullah A1 - Muhammad, Noor A1 - Alam Khan, Sher A1 - Nawaz, Hamed A1 - Khan, Ajmal A1 - Ahmad, Naseer A1 - Kolb, Susanne M. A1 - Kühlewein, Laura A1 - Labonne, Jonathan D. J. A1 - Layman, Lawrence C. A1 - Hofrichter, Michaela A. H. A1 - Röder, Tabea A1 - Dittrich, Marcus A1 - Müller, Tobias A1 - Graves, Tyler D. A1 - Kong, Il-Keun A1 - Nanda, Indrajit A1 - Kim, Hyung-Goo A1 - Haaf, Thomas T1 - Genetic Spectrum of Syndromic and Non-Syndromic Hearing Loss in Pakistani Families JF - Genes N2 - The current molecular genetic diagnostic rates for hereditary hearing loss (HL) vary considerably according to the population background. Pakistan and other countries with high rates of consanguineous marriages have served as a unique resource for studying rare and novel forms of recessive HL. A combined exome sequencing, bioinformatics analysis, and gene mapping approach for 21 consanguineous Pakistani families revealed 13 pathogenic or likely pathogenic variants in the genes GJB2, MYO7A, FGF3, CDC14A, SLITRK6, CDH23, and MYO15A, with an overall resolve rate of 61.9%. GJB2 and MYO7A were the most frequently involved genes in this cohort. All the identified variants were either homozygous or compound heterozygous, with two of them not previously described in the literature (15.4%). Overall, seven missense variants (53.8%), three nonsense variants (23.1%), two frameshift variants (15.4%), and one splice-site variant (7.7%) were observed. Syndromic HL was identified in five (23.8%) of the 21 families studied. This study reflects the extreme genetic heterogeneity observed in HL and expands the spectrum of variants in deafness-associated genes. KW - genetic diagnosis KW - consanguinity KW - genome-wide linkage analysis KW - hearing loss KW - Pakistan KW - exome sequencing Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219293 SN - 2073-4425 VL - 11 IS - 11 ER - TY - JOUR A1 - Fleischmann, Pauline N. A1 - Grob, Robin A1 - Rössler, Wolfgang T1 - Kompass im Kopf : wie Wüstenameisen lernen heimzukehren JF - Biologie in unserer Zeit N2 - Erfolgreiche räumliche Orientierung ist für viele Tiere eine alltägliche Herausforderung. Cataglyphis‐Wüstenameisen sind bekannt für ihre Navigationsfähigkeiten, mit deren Hilfe sie nach langen Futtersuchläufen problemlos zum Nest zurückfinden. Wie aber nehmen naive Ameisen ihre Navigationssysteme in Betrieb? Nach mehrwöchigem Innendienst im dunklen Nest werden sie zu Sammlerinnen bei hellem Sonnenschein. Dieser Wechsel erfordert einen drastischen Wandel im Verhalten sowie neuronale Veränderungen im Gehirn. Erfahrene Ameisen orientieren sich vor allem visuell, sie nutzen einen Himmelskompass und Landmarkenpanoramen. Daher absolvieren naive Ameisen stereotype Lernläufe, um ihren Kompass zu kalibrieren und die Nestumgebung kennenzulernen. Während der Lernläufe blicken sie wiederholt zum Nesteingang zurück und prägen sich so ihren Heimweg ein. Zur Ausrichtung ihrer Blicke nutzen sie das Erdmagnetfeld als Kompassreferenz. Cataglyphis‐Ameisen besitzen hierfür einen Magnetkompass, der bislang unbekannt war. N2 - Successful spatial orientation is a daily challenge for many animals. Cataglyphis desert ants are famous for their navi­gational performances. They return to the nest after exten­sive foraging trips without any problems. How do ants take their navigational systems into operation? After conducting different tasks in the dark nest for several weeks, they be­come foragers under bright sun light. This transition re­quires both a drastic switch in behavior and neuronal changes in the brain. Experienced foragers mainly rely on visual cues. They use a celestial compass and landmark panoramas. For that reason, naïve ants perform stereotype learning walks to calibrate their compass systems and ac­quire information about the nest’s surroundings. During their learning walks, the ants frequently look back to the nest entrance to learn the homing direction. For aligning their gazes, they use the earth’s magnetic field as a com­pass reference. This magnetic compass in Cataglyphis ants was previously unknown. KW - Cataglyphis-Wüstenameisen KW - Magnetkompass KW - Insektennavigation KW - Himmelskompass Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219260 SN - 1521-415X VL - 50 IS - 2 ER - TY - JOUR A1 - Krauss, Jochen A1 - Vikuk, Veronika A1 - Young, Carolyn A. A1 - Krischke, Markus A1 - Mueller, Martin J. A1 - Baerenfaller, Katja T1 - Epichloë endophyte infection rates and alkaloid content in commercially available grass seed mixtures in Europe JF - Microorganisms N2 - Fungal endophytes of the genus Epichloë live symbiotically in cool season grass species and can produce alkaloids toxic to insects and vertebrates, yet reports of intoxication of grazing animals have been rare in Europe in contrast to overseas. However, due to the beneficial resistance traits observed in Epichloë infected grasses, the inclusion of Epichloë in seed mixtures might become increasingly advantageous. Despite the toxicity of fungal alkaloids, European seed mixtures are rarely tested for Epichloë infection and their infection status is unknown for consumers. In this study, we tested 24 commercially available seed mixtures for their infection rates with Epichloë endophytes and measured the concentrations of the alkaloids ergovaline, lolitrem B, paxilline, and peramine. We detected Epichloë infections in six seed mixtures, and four contained vertebrate and insect toxic alkaloids typical for Epichloë festucae var. lolii infecting Lolium perenne. As Epichloë infected seed mixtures can harm livestock, when infected grasses become dominant in the seeded grasslands, we recommend seed producers to test and communicate Epichloë infection status or avoiding Epichloë infected seed mixtures. KW - Epichloë spp. KW - grass endophytes KW - cool-season grass species KW - infection rates KW - alkaloids KW - toxicity KW - livestock KW - horses KW - Lolium perenne KW - perennial ryegrass Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203323 SN - 2076-2607 VL - 8 IS - 4 ER -