Refine
Year of publication
- 2014 (105) (remove)
Document Type
- Journal article (75)
- Doctoral Thesis (30)
Language
- English (105) (remove)
Keywords
- gene expression (5)
- antibodies (3)
- ants (3)
- biodiversity (3)
- cancer (3)
- cytoskeleton (3)
- diversity (3)
- ecology (3)
- evolution (3)
- expression (3)
- metabolism (3)
- phosphorylation (3)
- proliferation (3)
- Bestäuber (2)
- Biodiversität (2)
- Bioinformatik (2)
- Echinococcus (2)
- Epigenetik (2)
- Hearing loss (2)
- Hörverlust (2)
- Kilimandscharo (2)
- Kilimanjaro (2)
- MAP-Kinase (2)
- Maus (2)
- Molekularbiologie (2)
- Neisseria gonorrhoeae (2)
- Regulation (2)
- Taufliege (2)
- Trypanosoma brucei (2)
- apis mellifera (2)
- bacteria (2)
- bees (2)
- binding (2)
- culture (2)
- drosophila melanogaster (2)
- foraging (2)
- fungal structure (2)
- fungi (2)
- immunoprecipitation (2)
- meiosis (2)
- membrane proteins (2)
- miRNA (2)
- pollination (2)
- protein (2)
- reveals (2)
- sequence alignment (2)
- telomeres (2)
- "-omics" (1)
- 3D (1)
- 3D microscopy (1)
- ARF tumor-suppressor induced lymphomagenes (1)
- Aberration (1)
- Ackerrandstreifen (1)
- African Trypanosomes (1)
- Alkaline phosphatase (1)
- Ameisen (1)
- Anticoagulants (1)
- Apoptosis (1)
- Argonaute (1)
- Arten-Energy-Theory (1)
- B cell receptors (1)
- BCL-X-L P53 (1)
- BDNF (1)
- Berger-Parker (1)
- Bestäubungsökologie (1)
- Bienen <Überfamilie> (1)
- Bildauflösung (1)
- Bioinformatics (1)
- Biologische Uhr (1)
- Biomarker (1)
- Blattschneiderameisen (1)
- Bombus (1)
- Bombus Spp. Hymenoptera (1)
- Bone regeneration (1)
- Botanischer Garten (1)
- Brain (1)
- Bumblebee (1)
- Butterfly (1)
- C-MYC (1)
- C-MYC PUMA (1)
- CCDC79 (1)
- CK2 (1)
- CLAVATA3 (1)
- Cestoda (1)
- Cestode (1)
- Chirurgie (1)
- Chlamydia (1)
- Chlamydia trachomatis (1)
- Chlamydia-trachomatis-Infektion (1)
- Chromatin (1)
- Chromosomal Passenger Complex (1)
- Circadian Rhythms (1)
- Climate Change (1)
- Coagulation factor IX (1)
- Coexpression (1)
- Cord blood-derived hematopoietic stem and progenitor cells (1)
- Coumarin (1)
- Cross-species analyses (1)
- Cytoskeleton Chromosomal Passenger Complex Interaction GAR Domain (1)
- DM-domain gene (1)
- DNA-binding domain (1)
- DNA-damage checkpoint (1)
- DNS-Schädigung (1)
- DOT1 methyltransferase (1)
- Demethylierung (1)
- Deregulierung (1)
- Deutschland (1)
- Dimension 3 (1)
- Diversity (1)
- Drosophila (1)
- Drosophila melanogaster (1)
- Drought (1)
- Dysplasie (1)
- ERK (1)
- Echinococcosis (1)
- Ectopic bone formation (1)
- Einfluss (1)
- Einzelmolekülmikroskopie (1)
- Embryonale Stammzelle (1)
- Epigenetic (1)
- Escherichia coli-derived recombinant human bone morphogenetic protein-2 (1)
- Evaluation (1)
- Evolution (1)
- Explorative analyses (1)
- FLS2 receptor (1)
- Fbw7 (1)
- Fluoreszenzmikroskopie (1)
- Foldamere (1)
- Foldamers (1)
- Forest management (1)
- French-Canadian patients (1)
- GAS2L3 (1)
- Gen notch (1)
- Gen-Knockout (1)
- Gene regulation (1)
- Gene sets (1)
- Genexpression (1)
- Genregulation (1)
- Germinative cell (1)
- Grasses (1)
- HIV (1)
- HIV-1 protease (1)
- HPA Axis (1)
- HUWE1 (1)
- HeLa cells (1)
- Hematopoietic stem cell ex-vivo expansion (1)
- Herbivory (1)
- Hey Proteine (1)
- Hey proteins (1)
- Hill's powers (1)
- Histon-Methyltransferase (1)
- Histone (1)
- Hochauflösendes Verfahren (1)
- Honeybee (1)
- Host-parasite interaction (1)
- Hydra <Polyp> (1)
- Hypopharyngeal glands (1)
- Hypophysen-Zwischenhirn-System (1)
- Hypothalamisch-hypophysäre Achse (1)
- Hämatopoese (1)
- Höhengradient (1)
- I-tasser (1)
- ITS2 (1)
- Il 4 (1)
- Immunohistochemistry (1)
- Improved survival (1)
- Innere Uhr (1)
- Insects (1)
- Insulin (1)
- KSR1 (1)
- Kenyon cells (1)
- Kidney cancer (1)
- Kinase inhibitor (1)
- Knockout <Molekulargenetik> (1)
- Knockout mouse (1)
- Knorpelzelle (1)
- Konstruktive Didaktik (1)
- Käfer (1)
- LCK (1)
- Labial glands (1)
- Landnutzungsgradient (1)
- Leaves (1)
- Legumes (1)
- Lernort (1)
- MAP Kinase Signaling (1)
- MAPK (1)
- MAPK signaling cascades (1)
- MIZ1 (1)
- MYC (1)
- Makrophage (1)
- Malaria (1)
- Massentrachten (1)
- Mbm (1)
- Meiose (1)
- Mesenchymzelle (1)
- Metabolic Modelling (1)
- Metabolischen Modellierung (1)
- Methylene blue (1)
- Mexican coffee plantations (1)
- Mikroskopie (1)
- Modellierung (1)
- Modifizierung (1)
- Molekulargenetik (1)
- Mucin (1)
- Mushroom bodies (1)
- Mutagenese (1)
- Myc (1)
- N-Myc (1)
- NF-KAPPA-B (1)
- Nanos (1)
- Neoblast (1)
- Nestbau (1)
- Neuroblast (1)
- Neuroblastom (1)
- Neuropeptide (1)
- Northeastern Costa Rica (1)
- Notch Signalweg (1)
- Notch signalling (1)
- Oocytes (1)
- Out-of-school learning settings (1)
- PALM (1)
- PEG chemical modification (1)
- PI3K (1)
- PPD (1)
- PRC2 (1)
- Phosphoproteine (1)
- Plant-herbivore interactions (1)
- Pollination (1)
- Polylactide-co-glycolide (1)
- Profiling (1)
- Prognose (1)
- Prognosis (1)
- Protein p53 (1)
- RAS (1)
- RCC (1)
- RNA extraction (1)
- RNA sequence (1)
- RNA splicing (1)
- RNA-SEQ (1)
- RNA-SEQ data (1)
- RNS-Interferenz (1)
- Raps (1)
- Receptor kinase (1)
- Rectal cancer (1)
- Renal cell carcinoma (1)
- Renin Angiotensin System (1)
- Renin-Angiotensin-Aldosteron-System (1)
- Renin-Angiotensin-System (1)
- Rescorla-Wagner model (1)
- SGNH hydrolase (1)
- SPR-Spektroskopie (1)
- SPRED2 (1)
- SREC-I (1)
- SUN1 (1)
- Salmonella-containing vacuole (SCV) (1)
- Saproxylic beetles (1)
- Saproxylophage (1)
- Schwebfliegen (1)
- Signaltransduktion (1)
- Sonnenblumen (1)
- Spectral Data Analysis (1)
- Spred Protein (1)
- Spred-Proteine (1)
- Spumaviren (1)
- Stationenarbeit (1)
- Stem cell (1)
- Stoffwechsel (1)
- Synaptinemal-Komplex (1)
- TERB1 (1)
- TLR4 (1)
- TME (1)
- Tanzania (1)
- Tapeworm (1)
- Teamwork (1)
- Termiten (1)
- Thrombozyt (1)
- Toll-like-Rezeptoren (1)
- Transkriptionsfaktor (1)
- Transposon (1)
- Tumour markers (1)
- VKORC1 (1)
- Virulenzfaktor (1)
- Vitamin K epoxide reductase (1)
- Vorläuferzellen (1)
- Wald (1)
- Warfarin (1)
- Werk (1)
- Y chromosome (1)
- Zellskelett (1)
- Zellteilung (1)
- Zellzyklus (1)
- Zutokin (1)
- aberration (1)
- abundance (1)
- acetyltransferase RTT109 (1)
- acoustic signals (1)
- activity rhythm (1)
- adaptive plasticity (1)
- african trypanosomes (1)
- age polyethism (1)
- agroecosystems (1)
- albinaria (1)
- alpha-helical structure (1)
- ambystoma opacum (1)
- amphibian metamorphosis (1)
- amyotrophic-lateral-sclerosis (1)
- analysis of variance (1)
- ant (1)
- antigenetic variation (1)
- antigenic variation (1)
- apoptosis (1)
- arbuscular mycorrhizal fungi (1)
- arginine (1)
- arthropods (1)
- aspergillus fumigatus (1)
- auxin (1)
- background odor (1)
- bee pollinators (1)
- behavior (1)
- beta-oxidation (1)
- binding protein (1)
- biodiversity index (1)
- biodiversity measure (1)
- biogenesis (1)
- bioinformatic (1)
- biological locomotion (1)
- biological sciences (1)
- biominarlization proteins (1)
- bird species richness (1)
- birth rates (1)
- botanical gardens (1)
- brain (1)
- breast-cancer cells (1)
- bumblebee nest density (1)
- butterfly euphydryas-aurinia (1)
- camponotus aethiops (1)
- cancer cell (1)
- cancer treatment (1)
- capacitance (1)
- carcinomas (1)
- carriage (1)
- cations (1)
- cell binding (1)
- cell biology (1)
- cell cultures (1)
- cell death (1)
- cell growth (1)
- cell membranes (1)
- cell-cycle arrest cancer therapy (1)
- chemical diversity (1)
- chemische Modifizierung (1)
- chemotherapy resistance (1)
- chi square tests (1)
- chlamydia trachomatis (1)
- chondrocytes (1)
- chromatin assembly factors (1)
- circadian oscillators (1)
- circadian rhythms (1)
- circular-dichroism (1)
- classical conditioning (1)
- clausiliidae (1)
- clumping factor-B (1)
- cohesin SMC1-Beta (1)
- colonies (1)
- colony (1)
- colorectal cancer (1)
- comb (1)
- commercial grades (1)
- communication (1)
- community structures (1)
- complex (1)
- complex-III (1)
- components (1)
- compound eye (1)
- concept maps (1)
- conceptual change (1)
- conifers (1)
- conservation (1)
- constraints (1)
- copy-number alteration (1)
- cotton rats (1)
- crop yield (1)
- crops (1)
- crosstalk (1)
- cul3 ring ligase (1)
- cycle regulation (1)
- cytokinesis (1)
- cytokinin (1)
- cytokinins (1)
- dSTORM (1)
- data sharing (1)
- data-bank (1)
- death rates (1)
- declines (1)
- denritic cells (1)
- density (1)
- dentichasmias busseolae (1)
- deprivation (1)
- determinant (1)
- developing country (1)
- developmental biology (1)
- developmental plasticity (1)
- developmental reprogramming (1)
- diagnosis (1)
- differentiation (1)
- digestive system (1)
- discrimination (1)
- dominant optic atrophy (1)
- drug discovery (1)
- dung beetle coleoptera (1)
- dye stains-all (1)
- dynamics (1)
- economy services (1)
- ecosystem service (1)
- ecosystem services (1)
- ecosystemservices (1)
- elevational gradient (1)
- embryos (1)
- enhance (1)
- envelope (1)
- environmental cues (1)
- enzyme-linked immunoassays (1)
- epithelial cells (1)
- essential genes (1)
- evolutionary mutant model (1)
- expression site attenuation (1)
- extinction risk (1)
- factor acetylhydrolase activity (1)
- fish (1)
- fish model (1)
- fission yeast (1)
- flow cytometry (1)
- flowers (1)
- fluorescence (1)
- fluorescence microscopy (1)
- foraging behavior (1)
- forecasting (1)
- forests (1)
- formica cunicularia (1)
- fragmented landscapes (1)
- fruit set (1)
- fruit-quality (1)
- fungal diseases (1)
- fungal pathogens (1)
- gene regulation (1)
- generalization (1)
- generation (1)
- genes and chromosomes (1)
- genome (1)
- geometric mean (1)
- global change (1)
- grasslands (1)
- growth (1)
- habitat destruction (1)
- habitat patch (1)
- habitat quality (1)
- habitats (1)
- helitron (1)
- herbivores (1)
- hippocampal neurons (1)
- hive (1)
- homologous chromosomes (1)
- homology modeling (1)
- honey (1)
- honey bees (1)
- honeybee (1)
- host cells (1)
- host-cells (1)
- human impact (1)
- human mineralocorticoid receptor (1)
- humidity (1)
- hypotonic (1)
- identification (1)
- idiopathic inflammatory myopathies (1)
- image correlation spectroscopy (1)
- immune receptors (1)
- immune response (1)
- in vitro kinase assay (1)
- in-vitro (1)
- in-vivo (1)
- in-vivo expression (1)
- inducible factor-I (1)
- infections (1)
- inhibitors (1)
- insects (1)
- instensively managed farmland (1)
- interaction networks (1)
- invertebrate herbivory (1)
- isotonic (1)
- katydids orthoptera (1)
- kidneys (1)
- lactate dehydrogenase (1)
- lactic acid bacteria (1)
- lactobacillus (1)
- land use (1)
- land-use (1)
- land-use change (1)
- language (1)
- larval density (1)
- leaf-cutting ant (1)
- learning at workstations (1)
- learning curve (1)
- lepidoptera (1)
- life history (1)
- life stage (1)
- linguistic morphology (1)
- lipid bilayer (1)
- lipogenesis (1)
- living cells (1)
- local enhancement (1)
- localization microscopy (1)
- location behavior (1)
- macrophage (1)
- major histocompatibility complex (1)
- malaria (1)
- mammalian septins (1)
- management (1)
- mass-flowering crops (1)
- mechanics (1)
- mechanisms (1)
- medaka (1)
- media geométrica (1)
- medical and biological imaging (1)
- medida de la biodiversidad (1)
- meiotic chromosome dynamics (1)
- melanoma (1)
- membrane characteristics (1)
- membrane organization (1)
- membrane potential (1)
- membrane structures (1)
- memory (1)
- menschlicher Einfluss (1)
- mesenchymal stem cells (1)
- messenger RNA (1)
- metapopulation (1)
- metastasis (1)
- miR-126 (1)
- miR-21 (1)
- miRNS (1)
- microvilli (1)
- mitofilin (1)
- mobility (1)
- model (1)
- modulating (1)
- mole crickets (1)
- molecular biology (1)
- molecular diversity (1)
- molecular mass (1)
- molecular-dynamics simulations (1)
- monoallelic expression (1)
- morphology (1)
- mosquito (1)
- mutation (1)
- nacreous layer formation (1)
- native pollinators (1)
- natural enemies (1)
- natural variation (1)
- naturnahe Habitate (1)
- nervous system (1)
- nest building (1)
- neurons (1)
- nonhost plant (1)
- nuclear import (1)
- nuclear-pore complexes (1)
- nympahlidae (1)
- oaks (1)
- odor marks (1)
- oilseed rape (1)
- olfaction (1)
- olyelectrolyte domains (1)
- oncogenic transformation (1)
- oncolytic viruses (1)
- organization (1)
- oryzias-latipes (1)
- parasite (1)
- patterns (1)
- perception (1)
- pharmacology (1)
- phenotypic plasticity (1)
- phosphorylation sites (1)
- phylogenetic trees (1)
- physical properties (1)
- pines (1)
- plant community composition (1)
- plant diversity (1)
- plant hormones (1)
- plantago lanceolata (1)
- platelet activation factor (1)
- platyfish (1)
- pollinators (1)
- polyelectrolyte domains (1)
- population (1)
- populations (1)
- post-harvest quality (1)
- predation (1)
- predation risk (1)
- predictive factors (1)
- presynapse (1)
- prey growth rate (1)
- primary biliary-cirrhosis (1)
- proboscis extension response (PER) (1)
- procambarus-clarkii (1)
- product specificity (1)
- profile distances (1)
- prolactin (1)
- protease (1)
- protein domains (1)
- protein-protein interactions (1)
- proteins (1)
- psycholinguistics (1)
- pulmonata (1)
- pupae (1)
- quality (1)
- rana temporaria populations (1)
- reconstruction (1)
- recruitment (1)
- red blood cells (1)
- regression analysis (1)
- regulation (1)
- renal cancer (1)
- renal cell carcinoma (1)
- replicative stress (1)
- resistance (1)
- resource use (1)
- rhythms (1)
- ribosome biogenesis (1)
- riesgo de extinción (1)
- rolling-circle transposons (1)
- saccharomyces cerevisiae (1)
- saccharomyes cerevisiae (1)
- saproxylic Coleoptera (1)
- scanning electron microscopy (1)
- scavender receptor (1)
- scientific computing (1)
- secondary structure (1)
- secreted effector protein (1)
- selection (1)
- self-organization (1)
- semi-natural habitats (1)
- sequence databases (1)
- sequential introduction (1)
- sex chromosomes (1)
- sex determination (1)
- sex-determining region (1)
- shannon index (1)
- shelf life (1)
- signaling (1)
- simpson's index (1)
- single molecule microscopy (1)
- single-trial learning (1)
- socioeconomic (1)
- sound production (1)
- species diversity (1)
- species gastropoda (1)
- species richness (1)
- species-energy-theory (1)
- spermatocytes (1)
- spiders (1)
- spliceosomes (1)
- splicing factors (1)
- squalius alburnoides (1)
- stable-isotope (1)
- stem cell niche (1)
- strawberry (1)
- structure prediction (1)
- sucrose responsiveness (1)
- sucrose sensitivity (1)
- sunflowers (1)
- super-resolution (1)
- super-resolution microscopy (1)
- superresolution (1)
- surface proteins (1)
- surface water (1)
- surgical and invasive medical procedures (1)
- surgical oncology (1)
- symbiotic fungus (1)
- synapse structure (1)
- synapsis (1)
- synaptic localization (1)
- synthetic lethality (1)
- synthetische Letalität (1)
- systematics (1)
- systemic sclerosis (1)
- systems biology (1)
- teichoic acids (1)
- telomere attachment (1)
- temperate forests (1)
- temporal spillover (1)
- termites (1)
- testis (1)
- tettigoniidae (1)
- therapy (1)
- thermoregulation (1)
- three-dimensional microscopy (1)
- tool (1)
- tousled-like kinases (1)
- toxins (1)
- transcription (1)
- transcription factor MIZ-1 (1)
- transfer RNA-synthetases (1)
- transgenic mice (1)
- transplantation (1)
- transposition (1)
- transposon mutagenesis (1)
- tree plantations (1)
- trees (1)
- triglyceride accumulation (1)
- tropical ecology (1)
- tropische Ökologie (1)
- tumor (1)
- two-color microscopy (1)
- tyrosine phosphorylation (1)
- ubiquitination (1)
- unstructured proteins (1)
- urban-rural gradient (1)
- vaccinia virus (1)
- variant detection (1)
- variant surface glycoprotein (VSG) (1)
- vibration (1)
- viral entry (1)
- viral replication (1)
- viral transmission and infection (1)
- virulence (1)
- virulence factors (1)
- visual cues (1)
- visual learning (1)
- vocabulary (1)
- volatiles (1)
- waggle dance (1)
- wild (1)
- wild bees (1)
- xanthurenic acid (1)
- xiphophorus maculatus (1)
- zebrafish (1)
- zeitlicher Spillover (1)
- Ökosystem (1)
- índice de biodiversidad (1)
Institute
- Theodor-Boveri-Institut für Biowissenschaften (105) (remove)
Sonstige beteiligte Institutionen
- DNA Analytics Core Facility, Biocenter, University of Würzburg, Würzburg, Germany (1)
- Department of Animal Ecology and Tropical Biology, University of Würzburg, Würzburg, Germany (1)
- Forschungsstation Fabrikschleichach (1)
- Institut für Tierökologie und Tropenbiologie (1)
- Interdisziplinäres Zentrum für Klinische Forschung (ZIKF), Würzburg (1)
- Klinische Mikrobiologie am Universitätsklinikum Erlangen (1)
Neisseria gonorrhoeae is a human-specific pathogen that causes gonorrhea. It is defined as a super bacterium by the WHO due to the emergence of gonococci that are resistant to a variety of antibiotics and a rapidly increasing infection incidence. Genome-wide investigation of neisserial gene essentiality and novel virulence factors is urgently required in order to identify new targets for anti-neisserial therapeutics. To identify essential genes and new virulence factors, a high-density mutant library in N. gonorrhoeae MS11 was generated by in vitro transposon mutagenesis. The transposon library harbors more than 100,000 individual mutants, a density that is unprecedented in gonococcal research. Essential genes in N. gonorrhoeae were determined by enumerating frequencies of transposon insertion sites (TIS) with Illumina deep sequencing (Tn-seq). Tn-seq indicated an average distance between adjacent TIS of 25 bp. Statistical analysis unequivocally demonstrated 781 genes that were significantly depleted in TIS and thus are essential for Neisseria survival. A subset of the genes was experimentally verified to comprise essential genes and thus support the outcome of the study. The hereby identified candidate essential genes thus may constitute excellent targets for the development of new antibiotics or vaccines.
In a second study, the transposon mutant library was applied in a genome-scale “negative-selection strategy” to identify genes that are involved in low phosphate-dependent invasion (LPDI). LPDI is dependent on the Neisseria porin subtype PorBIA which acts as an epithelial cell invasin in absence of phosphate and is associated with severe pathogenicity in disseminated gonococcal infections (DGI). Tn-seq demonstrated 98 genes, which were involved in adherence to host cells and 43 genes involved in host cell invasion. E.g. the hypothetical protein NGFG_00506, an ABC transporter ATP-binding protein NGFG_01643, as well as NGFG_04218 encoding a homolog of mafI in N. gonorrhoeae FA1090 were experimentally verified as new invasive factors in LPDI. NGFG_01605, a predicted protease, was identified to be a common factor involved in PorBIA, Opa50 and Opa57-mediated neisserial engulfment by the epithelial cells. Thus, this first systematic Tn-seq application in N. gonorrhoeae identified a set of previously unknown N. gonorrhoeae invasive factors which demonstrate molecular mechanisms of DGI.
Obligate intracellular bacteria depend entirely on nutrients from the host cell for their reproduction. Here, we show that obligate intracellular Chlamydia downregulate the central tumor suppressor p53 in human cells. This reduction of p53 levels is mediated by the PI3K-Akt signaling pathway, activation of HDM2, and subsequent proteasomal degradation of p53. The stabilization of p53 in human cells severely impaired chlamydial development and caused the loss of infectious particle formation. DNA-damage-induced p53 interfered with chlamydial development through downregulation of the pentose phosphate pathway (PPP). Increased expression of the PPP key enzyme glucose-6-phosphate dehydrogenase rescued the inhibition of chlamydial growth induced by DNA damage or stabilized p53. Thus, downregulation of p53 is a key event in the chlamydial life cycle that reprograms the host cell to create a metabolic environment supportive of chlamydial growth.
Deregulated expression of MYC is a driver of colorectal carcinogenesis, necessitating novel strategies to inhibit MYC function. The ubiquitin ligase HUWE1 (HECTH9, ARF-BP1, MULE) associates with both MYC and the MYC-associated protein MIZ1. We show here that HUWE1 is required for growth of colorectal cancer cells in culture and in orthotopic xenograft models. Using high-throughput screening, we identify small molecule inhibitors of HUWE1, which inhibit MYC-dependent transactivation in colorectal cancer cells, but not in stem and normal colon epithelial cells. Inhibition of HUWE1 stabilizes MIZ1. MIZ1 globally accumulates on MYC target genes and contributes to repression of MYC-activated target genes upon HUWE1 inhibition. Our data show that transcriptional activation by MYC in colon cancer cells requires the continuous degradation of MIZ1 and identify a novel principle that allows for inhibition of MYC function in tumor cells.
For social insects, colony performance is largely dependent on the quantity and quality of food intake and thus on the efficiency of its foragers. In addition to innate preferences and previous experience, foragers can use social information to decide when and where to forage. In some stingless bee (Meliponini) species, individual foraging decisions are shown to be influenced by the presence of social information at resource sites. In dual choice tests, we studied whether visual and/or olfactory cues affect individual decision-making in rigona corvina Cockerell and if this information is species-specific. We found that T. corvina foragers possess local enhancement: they are attracted by olfactory and visual cues released by conspecifics but avoid feeders associated with heterospecific individuals of the species Tetragona ziegleri (Friese). Overall, olfactory cues seem to be more important than visual cues, but information by visual cues alone is sufficient for discrimination.
Escherichia coli α-hemolysin (HlyA) is a pore-forming protein of 110 kDa belonging to the family of RTX toxins. A hydrophobic region between the amino acid residues 238 and 410 in the N-terminal half of HlyA has previously been suggested to form hydrophobic and/or amphipathic α-helices and has been shown to be important for hemolytic activity and pore formation in biological and artificial membranes. The structure of the HlyA transmembrane channel is, however, largely unknown. For further investigation of the channel structure, we deleted in HlyA different stretches of amino acids that could form amphipathic β-strands according to secondary structure predictions (residues 71–110, 158–167, 180–203, and 264–286). These deletions resulted in HlyA mutants with strongly reduced hemolytic activity. Lipid bilayer measurements demonstrated that HlyAΔ71–110 and HlyAΔ264–286 formed channels with much smaller single-channel conductance than wildtype HlyA, whereas their channel-forming activity was virtually as high as that of the wildtype toxin. HlyAΔ158–167 and HlyAΔ180–203 were unable to form defined channels in lipid bilayers. Calculations based on the single-channel data indicated that the channels generated by HlyAΔ71–110 and HlyAΔ264–286 had a smaller size (diameter about 1.4 to 1.8 nm) than wildtype HlyA channels (diameter about 2.0 to 2.6 nm), suggesting that in these mutants part of the channel-forming domain was removed. Osmotic protection experiments with erythrocytes confirmed that HlyA, HlyAΔ71–110, and HlyAΔ264–286 form defined transmembrane pores and suggested channel diameters that largely agreed with those estimated from the single-channel data. Taken together, these results suggest that the channel-forming domain of HlyA might contain β-strands, possibly in addition to α-helical structures.
Habitat quality affects the presence and size of butterfly populations. Resources for all life stages must be found in a given or few habitat patches. Southern festoon (Zerynthia polyxena) is a vulnerable, but locally abundant species in Hungary. The larva requires birthwort (Aristolochia clematitis) as food plant. We examined the small scale habitat use of adults and distribution of eggs and larvae among different vegetation types to reveal the requirements of the species in all life stages. Transect counts were conducted in a tree plantation complex comprising four types of vegetation. Number (+/- SE) of adults, eggs and larvae were lowest in poplar plantation (adult 0.3 +/- 0.2, egg 1.1 +/- 1.1, larva 0.6 +/- 0.3). Medium amount of butterflies were observed in open (adult 8.3 +/- 2.9, egg 3.1 +/- 2.6, larva 3.1 +/- 1.9) and black-locust (adult 9.4 +/- 4.2, egg 12.7 +/- 4.9, larva 4.1 +/- 1.1) habitat. Number of butterflies was highest in hummocks (adult 13.5 +/- 1.5, egg 12.9 +/- 5.7, larva 8.4 +/- 2.1). Adults avoided bare ground. We encountered most eggs in dense food plant patches with high plants. Food plant height also positively influenced the occurrence of the larvae. Although distribution of adults and juvenile forms showed quite similar patterns, we could also reveal some differences that caused by different environmental conditions in distinct vegetation types. Our study stresses the importance of habitat quality, which affects population size of butterflies even in a highly degraded habitat complex.
Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe
(2014)
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.
Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weevils capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weevils foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts.
Miz1 is a zinc finger transcription factor with an N-terminal POZ domain. Complexes with Myc, Bcl-6 or Gfi-1 repress expression of genes like Cdkn2b (p15(Ink4)) or Cd-kn1a (p21(Cip1)). The role of Miz1 in normal mammary gland development has not been addressed so far. Conditional knockout of the Miz1 POZ domain in luminal cells during pregnancy caused a lactation defect with a transient reduction of glandular tissue, reduced proliferation and attenuated differentiation. This was recapitulated in vitro using mouse mammary gland derived HC11 cells. Further analysis revealed decreased Stat5 activity in Miz1 Delta POZ mammary glands and an attenuated expression of Stat5 targets. Gene expression of the Prolactin receptor (PrlR) and ErbB4, both critical for Stat5 phosphorylation (pStat5) or pStat5 nuclear translocation, was decreased in Miz1 Delta POZ females. Microarray, ChIP-Seq and gene set enrichment analysis revealed a down-regulation of Miz1 target genes being involved in vesicular transport processes. Our data suggest that deranged intracellular transport and localization of PrlR and ErbB4 disrupt the Stat5 signalling pathway in mutant glands and cause the observed lactation phenotype.
The anti-silencing function protein 1 (Asf1) is a chaperone that forms a complex with histones H3 and H4 facilitating dimer deposition and removal from chromatin. Most eukaryotes possess two different Asf1 chaperones but their specific functions are still unknown. Trypanosomes, a group of early-diverged eukaryotes, also have two, but more divergent Asf1 paralogs than Asf1 of higher eukaryotes. To unravel possible different functions, we characterized the two Asf1 proteins in Trypanosoma brucei. Asf1A is mainly localized in the cytosol but translocates to the nucleus in S phase. In contrast, Asf1B is predominantly localized in the nucleus, as described for other organisms. Cytosolic Asf1 knockdown results in accumulation of cells in early S phase of the cell cycle, whereas nuclear Asf1 knockdown arrests cells in S/G2 phase. Overexpression of cytosolic Asf1 increases the levels of histone H3 and H4 acetylation. In contrast to cytosolic Asf1, overexpression of nuclear Asf1 causes less pronounced growth defects in parasites exposed to genotoxic agents, prompting a function in chromatin remodeling in response to DNA damage. Only the cytosolic Asf1 interacts with recombinant H3/H4 dimers in vitro. These findings denote the early appearance in evolution of distinguishable functions for the two Asf1 chaperons in trypanosomes.