Refine
Year of publication
- 2016 (291) (remove)
Document Type
- Article (190)
- Doctoral Thesis (58)
- Review (18)
- Postprint (16)
- Other (7)
- Habilitation Thesis (1)
- Master's Thesis (1)
Is part of the Bibliography
- yes (291)
Keywords
- Dictyostelium (5)
- adaptation (4)
- phytoplankton (4)
- translation (4)
- Arabidopsis (3)
- Arabidopsis thaliana (3)
- Coadaptation (3)
- Felidae (3)
- Germline transmission (3)
- Large fragment deletion (3)
- Multiplex mutagenesis (3)
- RNA-guided Cas9 (3)
- allelopathy (3)
- ancient DNA (3)
- equalizing and stabilizing mechanisms (3)
- maintenance of functional diversity (3)
- microtubules (3)
- niche and fitness differences (3)
- nucleus (3)
- secondary metabolites (3)
- supersaturated species coexistence (3)
- trait convergence and divergence (3)
- Amphibia (2)
- Animal movement (2)
- Antiphospholipid antibody (2)
- Antiphospholipid syndrome (2)
- Bacteriophage (2)
- Bioelectrocatalysis (2)
- Blasia (2)
- Brassicaceae (2)
- Campylomormyrus (2)
- Capsella (2)
- Centrosom (2)
- Chlamydomonas (2)
- Chytridiomycota (2)
- Climate change (2)
- Crotalus (2)
- Cyanobacteria (2)
- DNA methylation (2)
- Electron transfer (2)
- Electropolymerization (2)
- Epitope mapping (2)
- Flow cytometry (2)
- GPS data (2)
- Grassland (2)
- HeH-protein (2)
- IBM (2)
- Individual-based model (2)
- LEM-domain protein (2)
- Line immunoassay (2)
- Microsatellites (2)
- Mojave toxin (2)
- Molecularly imprinted polymers (2)
- Mormyridae (2)
- Nostoc (2)
- O-antigen (2)
- O-serotyping (2)
- Parameter estimation (2)
- Phase variation (2)
- Phospholipid binding proteins (2)
- Phylogeny (2)
- RNA-Seq (2)
- Rozellomycota (2)
- Salmonella Typhimurium (2)
- Sampling rate (2)
- Southeast Asia (2)
- Starch metabolism (2)
- Tailspike protein (2)
- acidophile (2)
- biogeography (2)
- cellulose fibers (2)
- centrosome (2)
- composite material (2)
- computational morphodynamics (2)
- cyanobacteria (2)
- database (2)
- dictyostelium (2)
- evolution (2)
- extremophile (2)
- fatty acid changes (2)
- finite element modeling (2)
- freshwater algae (2)
- global change (2)
- hybridization (2)
- introgression (2)
- jasmonic acid (2)
- lamin (2)
- light adaptation (2)
- lipid classes (2)
- mathematical modeling (2)
- mathematical modelling (2)
- mathematische Modellierung (2)
- microcystin (2)
- molecular evolution (2)
- molecularly imprinted polymers (2)
- nuclear lamina (2)
- nucleolus (2)
- pathogens (2)
- phylogeny (2)
- plant cell wall (2)
- priming (2)
- root hair initiation (2)
- salicylic acid (2)
- symbiosis (2)
- systems biology (2)
- transcription (2)
- transcription factor (2)
- venom (2)
- 16S rRNA (1)
- 3-end processing (1)
- A. tenuissima (1)
- AHL25 (1)
- ATML1 (1)
- Above-/below-ground interactions (1)
- Actin cytoskeleton (1)
- Adaptation (1)
- Adolescent growth (1)
- Agricultural intensification (1)
- AgroScapeLabs (1)
- Aldehyde oxidase (1)
- Aldehyde oxidoreductase (1)
- Algae-virus (1)
- Alternaria infectoria (1)
- Alternaria toxin sulfates (1)
- Amperometric sensor (1)
- Anguilla anguilla (1)
- Anisotropic growth (1)
- Annual plant communities (1)
- Anura (1)
- Apple (1)
- Aquatic habitats (1)
- Arctic (1)
- Arf-like protein 2 (ARL2) (1)
- Arf-like protein 3 (ARL3) (1)
- Artificial micro-RNA (1)
- Asia (1)
- Asparagales (1)
- AtExpA8 (1)
- Ausrichtung (1)
- Bacterial toxin (1)
- Beech fructification (1)
- Below-ground resources (1)
- Beta2 - glycoprotein I (1)
- Beta2-glycoprotein I (1)
- Bildanalyse (1)
- Bioclimatic envelope modelling (1)
- Biocompatibility (1)
- Biofuel cell (1)
- Biogeography (1)
- Bioinformatic (1)
- Biome (1)
- Biosensor (1)
- Biosensor array (1)
- Biosensors (1)
- Biosynthesis (1)
- Biotic interactions (1)
- Birds (1)
- Bmp (1)
- Body height (1)
- Body mass index (1)
- Body size (1)
- Bone morphogenetic proteins (BMP) (1)
- Borrelia burgdorferi (1)
- Brown trout (1)
- CCM (1)
- CNTs-based screen printed electrodes (1)
- CO2 concentrating mechanism (1)
- CO2 limitation (1)
- CO2 supply (1)
- CP75 (1)
- Camelus dromedarius (1)
- Cameroon (1)
- Cardiac development (1)
- Cavia aperea (1)
- Cell polarity (1)
- Cell volume (1)
- Centrosome (1)
- Chemometrics (1)
- Chlorella (1)
- Climate change manipulations (1)
- Clostridium difficile (1)
- Clustering (1)
- Coluteocarpeae (1)
- Common vole (1)
- Communities as complex adaptive systems (1)
- Community assembly (1)
- Community effect (1)
- Competitive hierarchies (1)
- Computational modelling (1)
- Consumer (1)
- Cryptomycota (1)
- Curculigo (1)
- Cyanotoxins (1)
- DELLA proteins (1)
- DON (1)
- Daphnia (1)
- Dark matter fungi (1)
- Data integration (1)
- Data standardisation and formatting (1)
- Datenanalyse und Statistik (1)
- Datenbank (1)
- Dehydration tolerance (1)
- Dehydrogenase (1)
- Delta mcyB mutant (1)
- Dendritic cells (1)
- Development (1)
- Developmental tempo (1)
- Dielektrophorese (1)
- Direct electron transfer (1)
- Discretization (1)
- Disease (1)
- Dissolved inorganic carbon (1)
- Dissolved organic carbon (1)
- Diversification (1)
- Drought (1)
- Drug delivery systems (1)
- Drug metabolism (1)
- Dynamic vegetation models (1)
- EC50 (1)
- East Africa (1)
- Eco-evolution (1)
- Eco-genetic modelling (1)
- Ecological theory (1)
- Ecosystem functioning (1)
- Electron relay (1)
- Electronic tongue (1)
- Endocardium (1)
- Endoreduplication (1)
- Endozoochory syndrome (1)
- Energiemangel (1)
- Enzyme electrode (1)
- Epidermis (1)
- Epitopmapping (1)
- Escherichia coli (1)
- Esterase (1)
- European bat species (1)
- Experiment description (1)
- Experimental environment (1)
- Experimental evidence (1)
- Experimental metadata (1)
- Fitness (1)
- Fitness gradient (1)
- Forest change (1)
- Formica lugubris (1)
- Freshwater algae (1)
- Freshwater fungi (1)
- Fruit shape (1)
- Functional bat group (1)
- Functional types (1)
- Fungal physiology and ecology (1)
- Fungal tree (1)
- G-quadruplexes (1)
- G-quadruplexes, (1)
- GMYC (1)
- Gene regulatory network (1)
- Genetics (1)
- Geometric morphometrics (1)
- Germany (1)
- Global Lake Ecological Observatory Network (GLEON) (1)
- Glucan, water dikinase (1)
- Glycopolymer brush (1)
- Glycosyltransferase (1)
- Graphtheorie (1)
- Greenhouse experiment (1)
- Growth hormone (1)
- Growth reference values (1)
- Gutmicrobiota (1)
- Gymnophiona (1)
- H3K4 methylation (1)
- HIV (1)
- HIV Erkrankung (1)
- HPLC-MS/MS (1)
- Habitat gradients (1)
- Heat stress response (1)
- Hemodynamics (1)
- Hexapoda (1)
- High-throughput next-generation sequencing (1)
- Homologous recombination (1)
- Honeybee (1)
- Honigbiene (1)
- Human Physiome (1)
- Human sulfite oxidase (1)
- Huntington disease (1)
- Hybrid nanofilms (1)
- Hybrid prediction (1)
- Hypopharyngeal gland (1)
- Immobilisierung (1)
- Immunogene Proteine (1)
- Immunogenic Proteins (1)
- In vivo biotinylation (1)
- Index Seminum (1)
- Insects (1)
- Integration sites (1)
- Javan leopard (1)
- Kettle hole (1)
- KoRV (1)
- Koexistenz Mechanismen (1)
- Kombinationstherapie (1)
- Kriging (1)
- Kruppel-like factor 2 (1)
- LASSO (1)
- LC-OCD-OND (1)
- LSU (1)
- Lactarius subgenus Plinthogali (1)
- Lake Stechlin (1)
- Land reform (1)
- Larix gmelinii (1)
- Leaf area index (1)
- Leber congenital amaurosis (1)
- Licht-induzierte (1)
- Light (1)
- Livestock (1)
- Localized surface plasmon resonance (1)
- Lumpiness in pattern formation and self-organization (1)
- Lynx (1)
- MADS-domain transcription factor (1)
- MHC diversity (1)
- Macrophytes (1)
- Maize (1)
- Markov model (1)
- Matrix model (1)
- Mechanisms (1)
- Mechanotransduction (1)
- Medicine (1)
- Mediterranean shrubland (1)
- Mediterranean temporary ponds (1)
- Mesophyll tissue (1)
- Microbeads (1)
- Microbial electrochemistry (1)
- Microcystis aeruginosa (1)
- Microfluidics (1)
- Microtubules (1)
- Microtus arvalis (1)
- Mid-Holocene (1)
- Migration (1)
- Mikrotubuli (1)
- Military areas (1)
- Minimum information recommendations (1)
- Mitose (1)
- Mitosis (1)
- Model analysis (1)
- Model complexity (1)
- Modelling (1)
- Moesin (1)
- Molybdo-flavoenzymes (1)
- Moment closure for trait-based aggregate model approaches (1)
- Mormyroidea (1)
- Mortality (1)
- Mouse (1)
- Multimodal trait distributions (1)
- Multiplexed assays (1)
- Multispecies-coalescent (1)
- Multivariate data analysis (1)
- Mycophagy (1)
- NE Germany (1)
- Nagoya-protocol (1)
- Namibia (1)
- Nanogel (1)
- Nanoparticle (1)
- Nanoparticle uptake (1)
- Nanoparticles (1)
- Nanostructuring (1)
- Nanotoxicology (1)
- Natura 2000 (1)
- Neisseria gonorrhoeae (1)
- Neisseria meningitidis (1)
- Next-generation modelling (1)
- Ni electrodes (1)
- Nicotinamide (1)
- Nitric oxide synthase-like activity (1)
- Nitro-tyrosine (1)
- Nitrogen (1)
- Noccaea (1)
- Nucleus (1)
- Nutrients (1)
- ODD model description (1)
- OPA1 (1)
- Offending (1)
- One Plan Approach (1)
- Organic matter (1)
- Overweight (1)
- PAM fluorometry (1)
- PEG model (1)
- Paracetamol (1)
- Paternal effects (1)
- Pathogenic detection (1)
- Peer group (1)
- Periphyton (1)
- Permafrost ecosystem (1)
- Phage Display (1)
- Pharmakokinetik (1)
- Phenacetin (1)
- Phenolic compounds (1)
- Phenomics (1)
- Phenothiazine (1)
- Phosphodiesterase delta-subunit (PDE delta) (1)
- Phosphoglucan, water dikinase (1)
- Phosphorus (1)
- Phosphorylierung (1)
- Plant diversity (1)
- Plant functional groups (1)
- Plant functional types (1)
- Plant performance (1)
- Plant phenotyping (1)
- Plastidial phosphorylase (1)
- Pleistocene (1)
- Plio-Pleistocene (1)
- Ploidy (1)
- Polyelektrolyt-Multischichten (1)
- Population cycle (1)
- Population history (1)
- Population-based model (1)
- Positive selection (1)
- Potato (1)
- Precipitation gradient (1)
- Probing living Staphylococcus aureus (1)
- Protein voltammetry (1)
- Proteindegradierung (1)
- Proteine (1)
- Proteinkinase (1)
- Proteins (1)
- Proteomics (1)
- Puumala virus (1)
- Rainfall niche (1)
- Random walk (1)
- Rangeland management (1)
- Reactive nitrogen species (1)
- Recombinant Antibodies (1)
- Redox polymer (1)
- Redox proteins (1)
- Redox sensitive proteins (1)
- Regression (1)
- Regulation (1)
- Regulierung der Genexpression (1)
- Reintroduction (1)
- Rekombinante Antikörper (1)
- Resource selection (1)
- Retinitis pigmentosa protein 2 (RP2) (1)
- Retroviral endogenization (1)
- Rewetting (1)
- Rezeptor (1)
- Ribosom (1)
- Ribosome profiling (1)
- Risikoabbildung (1)
- Robustness (1)
- Rod photoreceptor (1)
- Russulaceae (1)
- S-glutathionylation (1)
- S-nitrosylation (1)
- SCN4aa (1)
- SELEX (1)
- SLiCE (1)
- SSRs (1)
- STAT6 (1)
- Sarcopoterium spinosum (1)
- Savanna ecology (1)
- Savanna resilience (1)
- Savannen Resilienz (1)
- Scenedesmus (1)
- Screen-printed electrode (1)
- Seamless ligation cloning (1)
- Seasonality (1)
- Secondary structure (1)
- Seed germination (1)
- Sekundärmetabolite (1)
- Selection (1)
- Senior-LOken syndrome (1)
- Sensitivity analysis (1)
- Serotonin (1)
- Shape of trade-offs and stabilizing and disruptive selection (1)
- Shrub encroachment (1)
- Signaling (1)
- Simulation experiment (1)
- SnRK1 (1)
- Solanum tuberosum L. (1)
- Specialized metabolites (1)
- Species co-existence (1)
- Species complex (1)
- Species-delimitation (1)
- Stable isotopes (1)
- Stage-based model (1)
- Starch degradation (1)
- Starch granule (1)
- Starch phosphorylation (1)
- Starch synthase (1)
- Stimulierung von Zellen (1)
- Structured population model (1)
- Surface enhanced Raman spectroscopy (1)
- Surface imprinting (1)
- Survival (1)
- Synthetic biology (1)
- Systembiologie (1)
- Tadpoles (1)
- Target enrichment (1)
- Temporary pond (1)
- Th2 cells (1)
- The Netherlands (1)
- Thlaspi perfoliatum (1)
- Time-lag effects (1)
- Toba eruption (1)
- Toba volcanic eruption (1)
- Tolerance (1)
- TorD family (1)
- Toxicity (1)
- Trait heterogeneity (1)
- Trait-based approach (1)
- Transcription (1)
- Transcription factors (1)
- Transkriptomik (1)
- Translation (1)
- Triticum aestivum L. (1)
- Tyrosinase (1)
- Understanding (1)
- Ursus arctos (1)
- Ursus spelaeus (1)
- Vasculature (1)
- Vegetation continuum (1)
- Vegf (1)
- Verbuschung (1)
- VideoScan technology (1)
- Viverridae (1)
- Voice break (1)
- Voltage-gated sodium channel (1)
- Wassererosion (1)
- Wastewater (1)
- Wechselwirkungen (1)
- Wireworms (1)
- Xanthine oxidoreductase (1)
- XdhC (1)
- Y chromosome (1)
- YME1L1 (1)
- Zebrafish (1)
- Zellbiologie (1)
- Zellkern (1)
- Zoosporic fungi (1)
- Zytoskelett (1)
- abiotic soil factors (1)
- acI-B in Actinobacteria (1)
- acoustic telemetry (1)
- aggregation (1)
- alignment (1)
- altenuic acid (1)
- altertoxins (1)
- amyloid precursor protein (1)
- amyloid precursor-like protein (1)
- animal model (1)
- anisotropic growth (1)
- annual plant communities (1)
- anthropogenic admixture (1)
- anthropogenic exploitation (1)
- anthropometry (1)
- antipsychotics (1)
- aptamers (1)
- aptasensors (1)
- aquatic fungi (1)
- arabidopsis (1)
- arbuscular mycorrhizal fungi (1)
- archaeozoology (1)
- arms race (1)
- asexual reproduction (1)
- assay (1)
- autonomous pathway (1)
- bank vole (1)
- benthic food web (1)
- benthos (1)
- bet hedging (1)
- bilateral asymmetry (1)
- binding (1)
- biodiversity (1)
- biodiversity assessment (1)
- biodiversity ecosystem functioning (BEF) (1)
- bioelectrocatalysis (1)
- biofilm (1)
- biogeochemistry (1)
- biomass (1)
- biomass allocation (1)
- biomimetic recognition elements (1)
- bioremediation (1)
- biosensor (1)
- biosorption (1)
- biosynthesis (1)
- body height (1)
- body size (1)
- carbon acquisition (1)
- carbon budget (1)
- carbon cycle (1)
- cattle grazing (1)
- cell adhesion (1)
- cetaceans (1)
- chemical sensors (1)
- chlorophyll fluorescence (1)
- chromatin (1)
- cis-regulatory evolution (1)
- civet oil (1)
- climate manipulation (1)
- co-limitation (1)
- coastal erosion (1)
- coat colour (1)
- coevolution (1)
- coexistence mechanisms (1)
- collagen peptide mass fingerprinting (1)
- colony organization (1)
- community ecology (1)
- community effect on height (1)
- competition (1)
- complex food webs (1)
- conformational-changes (1)
- continuous pasture (1)
- copy numbers (1)
- crustaceans (1)
- cytoskeleton (1)
- data analysis and statistics (1)
- data standardisation and formatting (1)
- deep sequencing (1)
- defence (1)
- defense (1)
- degraded DNA (1)
- dementia (1)
- demographic history (1)
- development cooperation (1)
- diaptomid copepods (1)
- dielectrophoresis (1)
- diffusion (1)
- direct electron transfer (1)
- discontinuous migration (1)
- diversification (1)
- domestication (1)
- drug release (1)
- early warning signals (1)
- eco-evolutionary dynamics (1)
- ecological efficiency (1)
- ecosystem function (1)
- ecosystem processes (1)
- elbow breadth (1)
- electrokinetics (1)
- elektrokinetische Effekte (1)
- energy starvation (1)
- environmental adversity (1)
- environmental factor (1)
- environmental fluctuations (1)
- environmental trigger (1)
- enzymatic degradation (1)
- enzyme bioelectrocatalysis (1)
- epigenetics (1)
- equus caballus (1)
- essential nutrient (1)
- eusociality (1)
- evolutionary history (1)
- experiment description (1)
- experimental metadata (1)
- extinction (1)
- extinctions (1)
- facilitation (1)
- factorial design (1)
- filtration rate (1)
- fish migration (1)
- fitness (1)
- flight (1)
- flight efficiency (1)
- flowering time (1)
- fluctuating selection (1)
- fluorescence recovery after photobleaching (1)
- food quality (1)
- frameshifting (1)
- fruit shape (1)
- functional traits (1)
- fungal diversity (1)
- gene expression control (1)
- gene knock-out (1)
- generalists (1)
- generalized linear model (1)
- gibberellin (1)
- graph theory (1)
- grassland (1)
- green-i (1)
- growth control (1)
- growth rate (1)
- habitat specificity (1)
- handedness (1)
- handling effect (1)
- heat shock transcription factor (1)
- heat stress response (1)
- heterogeneity (1)
- hexapoda (1)
- high-frequency sensors (1)
- historic growth studies (1)
- historical demography (1)
- homing (1)
- honey bee (1)
- horse (1)
- host-virus (1)
- hyaluronic acid (1)
- hybrid capture (1)
- hybridization capture (1)
- hydrogen peroxide (1)
- hyper spectral (1)
- image analysis (1)
- immobilization (1)
- in vitro selection (1)
- inequality (1)
- infectivity (1)
- information technology (1)
- inorganic carbon uptake kinetics (1)
- insects (1)
- intellectual disability (1)
- interactions (1)
- intraspecific variation (1)
- intronic cis-regulatory element (1)
- juvenile mortality (1)
- kin selection (1)
- kontrollierte Freisetzung von Biomolekülen (1)
- lake ecosystem (1)
- land use impact (1)
- last glacial maximum (1)
- laterality (1)
- layer-by-layer (1)
- left handers (1)
- life history (1)
- light-triggered (1)
- lipid-binding protein (1)
- living collections management (1)
- locomotion (1)
- lowland fen (1)
- mRNA Degradierung (1)
- mRNA degradation (1)
- macroporous ITO electrodes (1)
- managing big data (1)
- mathematische Modelierung (1)
- mathematisches Modellierung (1)
- meadow (1)
- mechanism (1)
- memory (1)
- metabarcoding (1)
- microcystis (1)
- microelectrode (1)
- microviridins (1)
- migration (1)
- minimum information recommendations (1)
- mitochondrial fragmentation (1)
- mitochondriopathy (1)
- mitogenomes (1)
- mitosis (1)
- modelling (1)
- modified Alternaria toxins (1)
- molybdenum cofactor (1)
- molybdoenzyme maturation (1)
- morphological evolution (1)
- mtDNA (1)
- multi-nutrient limitation (1)
- multilayer films (1)
- mycotoxin profile (1)
- natural organic matter (1)
- natural products (1)
- natural resource management (1)
- neotypification (1)
- nephrocystins (1)
- nephronophthisis (1)
- nephropathia epidemica (1)
- neuronal adhesion (1)
- next generation sequencing (1)
- next generation sequencing (NGS) (1)
- next-generation sequencing (1)
- niche shifts (1)
- non-academic capacity development (1)
- nonmodel species (1)
- number and brightness (1)
- nurse plant (1)
- nutrient limitation (1)
- nutritional ecology (1)
- optic atrophy (1)
- optimization (1)
- organic farming (1)
- outbreak (1)
- oxygen reduction reaction (1)
- pH-dependent electrochemistry (1)
- pH-drift (1)
- paleogenetics (1)
- parameter estimation (1)
- parental care (1)
- participatory ecological-economic modelling (1)
- participatory research (1)
- pelagic food web (1)
- peptides (1)
- performance landscape (1)
- permafrost (1)
- persistence (1)
- personalised medicine (1)
- personalisierte Medizin (1)
- pharmacokinetics (1)
- phenotypic plasticity (1)
- phosphatases (1)
- phosphate limitation (1)
- phosphorylation (1)
- photoreceptor (1)
- photosynthesis response (1)
- phylogeography (1)
- pinniped (1)
- plankton (1)
- plant community (1)
- plant development (1)
- plant functional traits (1)
- plant growth (1)
- plant invasion (1)
- plant phenotyping (1)
- plant productivity (1)
- plant science (1)
- plant species richness (1)
- plant synthetic biology (1)
- plant-pathogen interaction (1)
- plant-soil (belowground) interactions (1)
- plant-soil interaction (1)
- plasticity (1)
- poly(A) polymerase (1)
- polyadenylation (1)
- polydomy (1)
- polylysine (1)
- polymer-modified electrode (1)
- population structure (1)
- predictive analysis (1)
- profiling buoys (1)
- protein (1)
- protein biosynthesis (1)
- protein degradation (1)
- protein kinase (1)
- protein trafficking (Golgi) (1)
- proteins (1)
- prädiktive Analyse (1)
- public good (1)
- qRT-PCR (1)
- rainfall gradient (1)
- reactive oxygen species (1)
- receptors (1)
- reed (1)
- repositories (1)
- reproducible science (1)
- reproductive investment (1)
- reproductive system (1)
- resistance (1)
- reskilling (1)
- retinal degeneration (1)
- ribosome (1)
- ribosome profiling (1)
- rice (1)
- risk mapping (1)
- role play (1)
- root traits (1)
- rotational pasture (1)
- rotifers (1)
- savanna rangeland (1)
- scanning electrochemical microscopy (1)
- seasonal migration (1)
- secondary structure (1)
- secular trend (1)
- sediment (1)
- seed exchange (1)
- seeding (1)
- self-assembled monolayer (1)
- semi-arid (1)
- semipermeable (1)
- sequence enrichment (1)
- serotonin (1)
- service infrastructure (1)
- single cell genomics (1)
- size structure (1)
- social organization (1)
- social signals (1)
- sociality (1)
- soil aggregation (1)
- soil biota (1)
- specialists (1)
- species distribution modelling (1)
- species diversity (1)
- species identification (1)
- specific chaperons (1)
- specific root length (1)
- stable isotopes (1)
- standard deviation for height (1)
- standards (1)
- standing variation; organ-specific evolution (1)
- stimulation of cells (1)
- stochastic modeling (1)
- stochastische Modellierung (1)
- stoichiometry (1)
- strategic growth adjustment (1)
- stress signalling (1)
- stress tolerance (1)
- stress-gradient hypothesis (1)
- substitutable resource (1)
- subsurface chlorophyll maximum (1)
- succession (1)
- sulfonated polyanilines (1)
- synergistic effect (1)
- synthetic biology (1)
- tannic acid (1)
- taxonomy (1)
- temperature increase (1)
- temporal effects (1)
- terrestrial subsidy (1)
- thermoregulation (1)
- trade-off (1)
- transcriptional memory (1)
- transcriptomics (1)
- transgenerational epigenetic inheritance (1)
- transgenic plants (1)
- transient reporter gene assays (1)
- translation regulation (1)
- trinucleotide repeat disease (1)
- trophic interactions (1)
- unc-119 homolog (C. elegans) (UNC119A) (1)
- upper extremity (1)
- urban soil erosion (1)
- urbane Bodenerosion (1)
- variability (1)
- vertical migration (1)
- viral fitness (1)
- water erosion (1)
- water sample (1)
- water-stable aggregates (1)
- wet grassland (1)
- wheat (1)
- white stork (1)
- wild dromedary (1)
- wildland conservation (1)
- winter fish kill (1)
- woody encroachment (1)
- xanthine dehydrogenase (1)
- yellow Zea mays (1)
- zinc (1)
- zooarchaeology by mass spectrometry (1)
- zooplankton (1)
Institute
- Institut für Biochemie und Biologie (291) (remove)
Für alle Organismen ist die Aufrechterhaltung ihres energetischen Gleichgewichts unter fluktuierenden Umweltbedingungen lebensnotwendig. In Eukaryoten steuern evolutionär konservierte Proteinkinasen, die in Pflanzen als SNF1-RELATED PROTEIN KINASE1 (SnRK1) bezeichnet werden, die Adaption an Stresssignale aus der Umwelt und an die Limitierung von Nährstoffen und zellulärer Energie. Die Aktivierung von SnRK1 bedingt eine umfangreiche transkriptionelle Umprogrammierung, die allgemein zu einer Repression energiekonsumierender Prozesse wie beispielsweise Zellteilung und Proteinbiosynthese und zu einer Induktion energieerzeugender, katabolischer Stoffwechselwege führt. Wie unterschiedliche Signale zu einer generellen sowie teilweise gewebe- und stressspezifischen SnRK1-vermittelten Antwort führen ist bisher noch nicht ausreichend geklärt, auch weil bislang nur wenige Komponenten der SnRK1-Signaltransduktion identifiziert wurden. In dieser Arbeit konnte ein Protein-Protein-Interaktionsnetzwerk um die SnRK1αUntereinheiten aus Arabidopsis AKIN10/AKIN11 etabliert werden. Dadurch wurden zunächst Mitglieder der pflanzenspezifischen DUF581-Proteinfamilie als Interaktionspartner der SnRK1α-Untereinheiten identifiziert. Diese Proteine sind über ihre konservierte DUF581Domäne, in der ein Zinkfinger-Motiv lokalisiert ist, fähig mit AKIN10/AKIN11 zu interagieren. In planta Ko-Expressionsanalysen zeigten, dass die DUF581-Proteine eine Verschiebung der nucleo-cytoplasmatischen Lokalisierung von AKIN10 hin zu einer nahezu ausschließlichen zellkernspezifischen Lokalisierung begünstigen sowie die Ko-Lokalisierung von AKIN10 und DUF581-Proteinen im Nucleus. In Bimolekularen Fluoreszenzkomplementations-Analysen konnte die zellkernspezifische Interaktion von DUF581-Proteinen mit SnRK1α-Untereinheiten in planta bestätigt werden. Außerhalb der DUF581-Domäne weisen die Proteine einander keine große Sequenzähnlichkeit auf. Aufgrund ihrer Fähigkeit mit SnRK1 zu interagieren, dem Fehlen von SnRK1Phosphorylierungsmotiven sowie ihrer untereinander sehr variabler gewebs-, entwicklungs- und stimulusspezifischer Expression wurde für DUF581-Proteine eine Funktion als Adaptoren postuliert, die unter bestimmten physiologischen Bedingungen spezifische Substratproteine in den SnRK1-Komplex rekrutieren. Auf diese Weise könnten DUF581Proteine die Interaktion von SnRK1 mit deren Zielproteinen modifizieren und eine Feinjustierung der SnRK1-Signalweiterleitung ermöglichen. Durch weiterführende Interaktionsstudien konnten DUF581-interagierende Proteine darunter Transkriptionsfaktoren, Proteinkinasen sowie regulatorische Proteine gefunden werden, die teilweise ebenfalls Wechselwirkungen mit SnRK1α-Untereinheiten aufzeigten. Im Rahmen dieser Arbeit wurde eines dieser Proteine für das eine Beteiligung an der SnRK1Signalweiterleitung als Transkriptionsregulator vermutet wurde näher charakterisiert. STKR1 (STOREKEEPER RELATED 1), ein spezifischer Interaktionspartner von DUF581-18, gehört zu einer pflanzenspezifischen Leucin-Zipper-Transkriptionsfaktorfamilie und interagiert in Hefe sowie in planta mit SnRK1. Die zellkernspezifische Interaktion von STKR1 und AKIN10 in Pflanzen unterstützt die Vermutung der kooperativen Regulation von Zielgenen. Weiterhin stabilisierte die Anwesenheit von AKIN10 die Proteingehalte von STKR1, das wahrscheinlich über das 26S Proteasom abgebaut wird. Da es sich bei STKR1 um ein Phosphoprotein mit SnRK1-Phosphorylierungsmotiv handelt, stellt es sehr wahrscheinlich ein SnRK1-Substrat dar. Allerdings konnte eine SnRK1-vermittelte Phosphorylierung von STKR1 in dieser Arbeit nicht gezeigt werden. Der Verlust von einer Phosphorylierungsstelle beeinflusste die Homo- und Heterodimerisierungsfähigkeit von STKR1 in Hefeinteraktionsstudien, wodurch eine erhöhte Spezifität der Zielgenregulation ermöglicht werden könnte. Außerdem wurden Arabidopsis-Pflanzen mit einer veränderten STKR1-Expression phänotypisch, physiologisch und molekularbiologisch charakterisiert. Während der Verlust der STKR1-Expression zu Pflanzen führte, die sich kaum von Wildtyp-Pflanzen unterschieden, bedingte die konstitutive Überexpression von STKR1 ein stark vermindertes Pflanzenwachstum sowie Entwicklungsverzögerungen hinsichtlich der Blühinduktion und Seneszenz ähnlich wie sie auch bei SnRK1α-Überexpression beschrieben wurden. Pflanzen dieser Linien waren nicht in der Lage Anthocyane zu akkumulieren und enthielten geringere Gehalte an Chlorophyll und Carotinoiden. Neben einem erhöhten nächtlichen Stärkeumsatz waren die Pflanzen durch geringere Saccharosegehalte im Vergleich zum Wildtyp gekennzeichnet. Eine Transkriptomanalyse ergab, dass in den STKR1-überexprimierenden Pflanzen unter Energiemangelbedingungen, hervorgerufen durch eine verlängerte Dunkelphase, eine größere Anzahl an Genen im Vergleich zum Wildtyp differentiell reguliert war als während der Lichtphase. Dies spricht für eine Beteiligung von STKR1 an Prozessen, die während der verlängerten Dunkelphase aktiv sind. Ein solcher ist beispielsweise die SnRK1-Signaltransduktion, die unter energetischem Stress aktiviert wird. Die STKR1Überexpression führte zudem zu einer verstärkten transkriptionellen Induktion von Abwehrassoziierten Genen sowie NAC- und WRKY-Transkriptionsfaktoren nach verlängerter Dunkelphase. Die Transkriptomdaten deuteten auf eine stimulusunabhängige Induktion von Abwehrprozessen hin und konnten eine Erklärung für die phänotypischen und physiologischen Auffälligkeiten der STKR1-Überexprimierer liefern.
Species can adjust their traits in response to selection which may strongly influence species coexistence. Nevertheless, current theory mainly assumes distinct and time-invariant trait values. We examined the combined effects of the range and the speed of trait adaptation on species coexistence using an innovative multispecies predator–prey model. It allows for temporal trait changes of all predator and prey species and thus simultaneous coadaptation within and among trophic levels. We show that very small or slow trait adaptation did not facilitate coexistence because the stabilizing niche differences were not sufficient to offset the fitness differences. In contrast, sufficiently large and fast trait adaptation jointly promoted stable or neutrally stable species coexistence. Continuous trait adjustments in response to selection enabled a temporally variable convergence and divergence of species traits; that is, species became temporally more similar (neutral theory) or dissimilar (niche theory) depending on the selection pressure, resulting over time in a balance between niche differences stabilizing coexistence and fitness differences promoting competitive exclusion. Furthermore, coadaptation allowed prey and predator species to cluster into different functional groups. This equalized the fitness of similar species while maintaining sufficient niche differences among functionally different species delaying or preventing competitive exclusion. In contrast to pre-
vious studies, the emergent feedback between biomass and trait dynamics enabled supersaturated coexistence for a broad range of potential trait adaptation and parameters. We conclude that accounting for trait adaptation may explain stable and supersaturated species coexistence for a broad range of environmental conditions in natural systems when the absence of such adaptive changes would preclude it. Small trait changes, coincident with those that may occur within many natural populations, greatly enlarged the number of coexisting species.
Species can adjust their traits in response to selection which may strongly influence species coexistence. Nevertheless, current theory mainly assumes distinct and time-invariant trait values. We examined the combined effects of the range and the speed of trait adaptation on species coexistence using an innovative multispecies predator–prey model. It allows for temporal trait changes of all predator and prey species and thus simultaneous coadaptation within and among trophic levels. We show that very small or slow trait adaptation did not facilitate coexistence because the stabilizing niche differences were not sufficient to offset the fitness differences. In contrast, sufficiently large and fast trait adaptation jointly promoted stable or neutrally stable species coexistence. Continuous trait adjustments in response to selection enabled a temporally variable convergence and divergence of species traits; that is, species became temporally more similar (neutral theory) or dissimilar (niche theory) depending on the selection pressure, resulting over time in a balance between niche differences stabilizing coexistence and fitness differences promoting competitive exclusion. Furthermore, coadaptation allowed prey and predator species to cluster into different functional groups. This equalized the fitness of similar species while maintaining sufficient niche differences among functionally different species delaying or preventing competitive exclusion. In contrast to previous studies, the emergent feedback between biomass and trait dynamics enabled supersaturated coexistence for a broad range of potential trait adaptation and parameters. We conclude that accounting for trait adaptation may explain stable and supersaturated species coexistence for a broad range of environmental conditions in natural systems when the absence of such adaptive changes would preclude it. Small trait changes, coincident with those that may occur within many natural populations, greatly enlarged the number of coexisting species.
Characterization of the Clp protease complex and identification of putative substrates in N. tabacum
(2016)
Among the bloom-forming and potentially harmful cyanobacteria, the genus Microcystis represents a most diverse taxon, on the genomic as well as on morphological and secondary metabolite levels. Microcystis communities are composed of a variety of diversified strains. The focus of this study lies on potential interactions between Microcystis representatives and the roles of secondary metabolites in these interaction processes.
The role of secondary metabolites functioning as signaling molecules in the investigated interactions is demonstrated exemplary for the prevalent hepatotoxin microcystin. The extracellular and intracellular roles of microcystin are tested in microarray-based transcriptomic approaches. While an extracellular effect of microcystin on Microcystis transcription is confirmed and connected to a specific gene cluster of another secondary metabolite in this study, the intracellularly occurring microcystin is related with several pathways of the primary metabolism. A clear correlation of a microcystin knockout and the SigE-mediated regulation of carbon metabolism is found. According to the acquired transcriptional data, a model is proposed that postulates the regulating effect of microcystin on transcriptional regulators such as the alternative sigma factor SigE, which in return captures an essential role in sugar catabolism and redox-state regulation.
For the purpose of simulating community conditions as found in the field, Microcystis colonies are isolated from the eutrophic lakes near Potsdam, Germany and established as stably growing under laboratory conditions. In co-habitation simulations, the recently isolated field strain FS2 is shown to specifically induce nearly immediate aggregation reactions in the axenic lab strain Microcystis aeruginosa PCC 7806. In transcriptional studies via microarrays, the induced expression program in PCC 7806 after aggregation induction is shown to involve the reorganization of cell envelope structures, a highly altered nutrient uptake balance and the reorientation of the aggregating cells to a heterotrophic carbon utilization, e.g. via glycolysis. These transcriptional changes are discussed as mechanisms of niche adaptation and acclimation in order to prevent competition for resources.
Das biogene Amin Serotonin (5-Hydroxytryptamin, 5-HT) agiert als wichtiger chemischer Botenstoff bei einer Vielzahl von Organismen. Das durch 5 HT vermittelte Signal wird dabei durch spezifische Rezeptoren wahrgenommen und in eine zelluläre Reaktion umgesetzt. Diese 5 HT Rezeptoren gehören überwiegend zur Familie der G Protein gekoppelten Rezeptoren (GPCRs). Die Honigbiene Apis mellifera bietet unter anderem aufgrund ihrer eusozialen Lebensweise vielfältige Ansatzpunkte zur Erforschung der Funktionen des serotonergen Systems in Insekten. Bei A. mellifera wurden bereits vier 5-HT-Rezeptor-Subtypen beschrieben und molekular sowie pharmakologisch charakterisiert: Am5 HT1A, Am5 HT2α, Am5 HT2β und Am5 HT7. Ziel dieser Arbeit war es, gewebespezifische sowie alters- und tageszeitabhängige Expressionsmuster der 5 HT Rezeptor-Subtypen zu untersuchen, um zu einem umfassenden Verständnis des serotonergen Systems der Honigbiene beizutragen und eine Basis zur Hypothesenentwicklung für mögliche physiologische Funktionen zu schaffen.
Es wurde die Expression der 5 HT Rezeptorgene sowohl im zentralen Nervensystem, als auch in Teilen des Verdauungs-, Exkretions- und Speicheldrüsensystems gemessen. Dabei konnte gezeigt werden, dass die untersuchten 5-HT-Rezeptor-Subtypen generell weit im Organismus der Honigbiene verbreitet sind. Interessanterweise unterschieden sich die untersuchten Gewebe hinsichtlich der mRNA-Expressionsmuster der untersuchten Rezeptoren. Während beispielsweise im Gehirn Am5 ht1A und Am5 ht7 stärker als Am5 ht2α und Am5 ht2β exprimiert wurden, zeigte sich in Darmgewebe ein umgekehrtes Muster.
Es war bereits bekannt, dass es bei der Expression der Am5-ht2-Gene zu alternativem Spleißen kommt. Dies führt zur Entstehung der verkürzten mRNA-Varianten Am5 ht2αΔIII und Am5 ht2βΔII. Die daraus resultierenden Proteine können nicht als funktionelle GPCRs agieren. Es konnte gezeigt werden, dass diese verkürzten Spleißvarianten dennoch ubiquitär in der Honigbiene exprimiert werden. Bemerkenswerterweise wurden gewebeübergreifende Ähnlichkeiten der Expressionsmuster der Spleißvarianten gegenüber deren zugehörigen Volllängenvarianten festgestellt, welche auf Funktionen der verkürzten Varianten in vivo hindeuten.
Im Hinblick auf die bei A. mellifera hauptsächlich altersbedingte Arbeitsteilung wurde die Expression der 5 HT Rezeptor-Subtypen in Gehirnen von unterschiedlich alten Arbeiterinnen mit unterschiedlichen sozialen Rollen verglichen. Während auf mRNA-Ebene keines der vier 5 HT Rezeptor-Subtypen eine altersabhängig unterschiedliche Expression zeigte, konnte für das Am5-HT1A-Protein eine höhere Konzentration in den Gehirnen älterer Tiere gefunden werden. Dies deutet auf eine posttranskriptionale Regulation der 5 HT1A Rezeptorexpression hin, welche im Zusammenhang mit der Arbeitsteilung stehen könnte.
Es erfolgte die Untersuchung tageszeitlicher Änderungen sowohl der Expression der 5 HT Rezeptor-Subtypen, als auch des biogenen Amins 5 HT selbst. Während es in den Gehirnen von Arbeiterinnen, welche unter natürlichen Bedingungen gehalten wurden, zu keiner tageszeitabhängigen Veränderung des 5 HT-Titers kam, zeigte die mRNA-Expression von Am5-ht2α und Am5-ht2β eine periodische Oszillation mit Zunahme während des Tages und Abnahme während der Nacht. Diese Regulation wird durch externe Faktoren hervorgerufen und ist nicht auf einen endogenen circadianen Rhythmus zurückzuführen. Dies ging aus der Wiederholung der Expressionsmessungen an Gehirnen von Bienen, welche unter konstanten Laborbedingungen gehalten wurden, hervor.
Weiterhin wurde die Beteiligung des serotonergen Systems an der Steuerung von Aspekten des circadianen lokomotorischen Aktivitätsrhythmus anhand von Verhaltensexperimenten untersucht. Mit 5 HT gefütterte Arbeiterinnen zeigten dabei unter konstanten Bedingungen eine längere Periode des Aktivitätsrhythmus als Kontrolltiere. Dies deutet auf einen Einfluss von 5 HT auf die Modulation der Synchronisation der inneren Uhr hin.
Die vorliegenden Ergebnisse tragen wesentlich zum tieferen Verständnis des serotonergen Systems der Honigbiene bei und bieten Ansatzpunkte für weitergehende Studien zur Funktion von 5 HT im Zusammenhang mit der Modulation von physiologischen Prozessen, Arbeitsteilung und circadianen Rhythmen.
Implementation of a plasmodesmata gatekeeper system, and its effect on intercellular transport
(2016)
Gene expression describes the process of making functional gene products (e.g. proteins or special RNAs) from instructions encoded in the genetic information (e.g. DNA). This process is heavily regulated, allowing cells to produce the appropriate gene products necessary for cell survival, adapting production as necessary for different cell environments. Gene expression is subject to regulation at several levels, including transcription, mRNA degradation, translation and protein degradation. When intact, this system maintains cell homeostasis, keeping the cell alive and adaptable to different environments. Malfunction in the system can result in disease states and cell death. In this dissertation, we explore several aspects of gene expression control by analyzing data from biological experiments. Most of the work following uses a common mathematical model framework based on Markov chain models to test hypotheses, predict system dynamics or elucidate network topology. Our work lies in the intersection between mathematics and biology and showcases the power of statistical data analysis and math modeling for validation and discovery of biological phenomena.
Over the last decades, the world’s population has been growing at a faster rate, resulting in increased urbanisation, especially in developing countries. More than half of the global population currently lives in urbanised areas with an increasing tendency. The growth of cities results in a significant loss of vegetation cover, soil compaction and sealing of the soil surface which in turn results in high surface runoff during high-intensity storms and causes the problem of accelerated soil water erosion on streets and building grounds. Accelerated soil water erosion is a serious environmental problem in cities as it gives rise to the contamination of aquatic bodies, reduction of ground water recharge and increase in land degradation, and also results in damages to urban infrastructures, including drainage systems, houses and roads. Understanding the problem of water erosion in urban settings is essential for the sustainable planning and management of cities prone to water erosion. However, in spite of the vast existence of scientific literature on water erosion in rural regions, a concrete understanding of the underlying dynamics of urban erosion still remains inadequate for the urban dryland environments.
This study aimed at assessing water erosion and the associated socio-environmental determinants in a typical dryland urban area and used the city of Windhoek, Namibia, as a case study. The study used a multidisciplinary approach to assess the problem of water erosion. This included an in depth literature review on current research approaches and challenges of urban erosion, a field survey method for the quantification of the spatial extent of urban erosion in the dryland city of Windhoek, and face to face interviews by using semi-structured questionnaires to analyse the perceptions of stakeholders on urban erosion.
The review revealed that around 64% of the literatures reviewed were conducted in the developed world, and very few researches were carried out in regions with extreme climate, including dryland regions. Furthermore, the applied methods for erosion quantification and monitoring are not inclusive of urban typical features and they are not specific for urban areas. The reviewed literature also lacked aspects aimed at addressing the issues of climate change and policies regarding erosion in cities. In a field study, the spatial extent and severity of an urban dryland city, Windhoek, was quantified and the results show that nearly 56% of the city is affected by water erosion showing signs of accelerated erosion in the form of rills and gullies, which occurred mainly in the underdeveloped, informal and semi-formal areas of the city. Factors influencing the extent of erosion in Windhoek included vegetation cover and type, socio-urban factors and to a lesser extent slope estimates. A comparison of an interpolated field survey erosion map with a conventional erosion assessment tool (the Universal Soil Loss Equation) depicted a large deviation in spatial patterns, which underlines the inappropriateness of traditional non-urban erosion tools to urban settings and emphasises the need to develop new erosion assessment and management methods for urban environments. It was concluded that measures for controlling water erosion in the city need to be site-specific as the extent of erosion varied largely across the city.
The study also analysed the perceptions and understanding of stakeholders of urban water erosion in Windhoek, by interviewing 41 stakeholders using semi-structured questionnaires. The analysis addressed their understanding of water erosion dynamics, their perceptions with regards to the causes and the seriousness of erosion damages, and their attitudes towards the responsibilities for urban erosion. The results indicated that there is less awareness of the process as a phenomenon, instead there is more awareness of erosion damages and the factors contributing to the damages. About 69% of the stakeholders considered erosion damages to be ranging from moderate to very serious. However, there were notable disparities between the private householders and public authority groups. The study further found that the stakeholders have no clear understanding of their responsibilities towards the management of the control measures and payment for the damages. The private householders and local authority sectors pointed fingers at each other for the responsibilities for erosion damage payments and for putting up prevention measures. The reluctance to take responsibility could create a predicament for areas affected, specifically in the informal settlements where land management is not carried out by the local authority and land is not owned by the occupants.
The study concluded that in order to combat urban erosion, it is crucial to understand diverse dynamics aggravating the process of urbanisation from different scales. Accordingly, the study suggests that there is an urgent need for the development of urban-specific approaches that aim at: (a) incorporating the diverse socio-economic-environmental aspects influencing erosion, (b) scientifically improving natural cycles that influence water storages and nutrients for plants in urbanised dryland areas in order to increase the amount of vegetation cover, (c) making use of high resolution satellite images to improve the adopted methods for assessing urban erosion, (d) developing water erosion policies, and (e) continuously monitoring the impact of erosion and the influencing processes from local, national and international levels.
Background
Non-typhoid Salmonella Typhimurium (S. Typhimurium) accounts for a high number of registered salmonellosis cases, and O-serotyping is one important tool for monitoring epidemiology and spread of the disease. Moreover, variations in glucosylated O-antigens are related to immunogenicity and spread in the host. However, classical autoagglutination tests combined with the analysis of specific genetic markers cannot always reliably register phase variable glucose modifications expressed on Salmonella O-antigens and additional tools to monitor O-antigen glucosylation phenotypes of S. Typhimurium would be desirable.
Results
We developed a test for the phase variable O-antigen glucosylation state of S. Typhimurium using the tailspike proteins (TSP) of Salmonella phages 9NA and P22. We used this ELISA like tailspike adsorption (ELITA) assay to analyze a library of 44 Salmonella strains. ELITA was successful in discriminating strains that carried glucose 1-6 linked to the galactose of O-polysaccharide backbone (serotype O1) from non-glucosylated strains. This was shown by O-antigen compositional analyses of the respective strains with mass spectrometry and capillary electrophoresis. The ELITA test worked rapidly in a microtiter plate format and was highly O-antigen specific. Moreover, TSP as probes could also detect glucosylated strains in flow cytometry and distinguish multiphasic cultures differing in their glucosylation state.
Conclusions
Tailspike proteins contain large binding sites with precisely defined specificities and are therefore promising tools to be included in serotyping procedures as rapid serotyping agents in addition to antibodies. In this study, 9NA and P22TSP as probes could specifically distinguish glucosylation phenotypes of Salmonella on microtiter plate assays and in flow cytometry. This opens the possibility for flow sorting of cell populations for subsequent genetic analyses or for monitoring phase variations during large scale O-antigen preparations necessary for vaccine production.
The impact of soil microbiota on plant species performance and diversity in semi-natural grasslands
(2016)
The horse is a fascinating animal symbolizing power, beauty, strength and grace. Among all the animal species domesticated the horse had the largest impact on the course of human history due to its importance for warfare and transportation. Studying the process of horse domestication contributes to the knowledge about the history of horses and even of our own species.
Research based on molecular methods has increasingly focused on the genetic basis of horse domestication. Mitochondrial DNA (mtDNA) analyses of modern and ancient horses detected immense maternal diversity, probably due to many mares that contributed to the domestic population. However, mtDNA does not provide an informative phylogeographic structure. In contrast, Y chromosome analyses displayed almost complete uniformity in modern stallions but relatively high diversity in a few ancient horses. Further molecular markers that seem to be well suited to infer the domestication history of horses or genetic and phenotypic changes during this process are loci associated with phenotypic traits.
This doctoral thesis consists of three different parts for which I analyzed various single nucleotide polymorphisms (SNPs) associated with coat color, locomotion or Y chromosomal variation of horses. These SNPs were genotyped in 350 ancient horses from the Chalcolithic (5,000 BC) to the Middle Ages (11th century). The distribution of the samples ranges from China to the Iberian Peninsula and Iceland. By applying multiplexed next-generation sequencing (NGS) I sequenced short amplicons covering the relevant positions: i) eight coat-color-associated mutations in six genes to deduce the coat color phenotype; ii) the so-called ’Gait-keeper’ SNP in the DMRT3 gene to screen for the ability to amble; iii) 16 SNPs previously detected in ancient horses to infer the corresponding haplotype. Based on these data I investigated the occurrence and frequencies of alleles underlying the respective phenotypes as well as Y chromosome haplotypes at different times and regions. Also, selection coefficients for several Y chromosome lineages or phenotypes were estimated.
Concerning coat color differences in ancient horses my work constitutes the most comprehensive study to date. I detected an increase of chestnut horses in the Middle Ages as well as differential selection for spotted and solid phenotypes over time which reflects changing human preferences.
With regard to ambling horses, the corresponding allele was present in medieval English and Icelandic horses. Based on these results I argue that Norse settlers, who frequently invaded parts of Britain, brought ambling individuals to Iceland from the British Isles which can be regarded the origin of this trait. Moreover, these settlers appear to have selected for ambling in Icelandic horses.
Relating to the third trait, the paternal diversity, these findings represent the largest ancient dataset of Y chromosome variation in non-humans. I proved the existence of several Y chromosome haplotypes in early domestic horses. The decline of Y chromosome variation coincides with the movement of nomadic peoples from the Eurasian steppes and later with different breeding practices in the Roman period.
In conclusion, positive selection was estimated for several phenotypes/lineages
in different regions or times which indicates that these were preferred by humans. Furthermore, I could successfully infer the distribution and dispersal of horses in association with human movements and actions. Thereby, a better understanding of the influence of people on the changing appearance and genetic diversity of domestic horses could be gained. My results also emphasize the close relationship of ancient genetics and archeology or history and that only in combination well-founded conclusions can be reached.
The population structure of the highly mobile marine mammal, the harbor porpoise (Phocoena phocoena), in the Atlantic shelf waters follows a pattern of significant isolation-by-distance. The population structure of harbor porpoises from the Baltic Sea, which is connected with the North Sea through a series of basins separated by shallow underwater ridges, however, is more complex. Here, we investigated the population differentiation of harbor porpoises in European Seas with a special focus on the Baltic Sea and adjacent waters, using a population genomics approach. We used 2872 single nucleotide polymorphisms (SNPs), derived from double digest restriction-site associated DNA sequencing (ddRAD-seq), as well as 13 microsatellite loci and mitochondrial haplotypes for the same set of individuals. Spatial principal components analysis (sPCA), and Bayesian clustering on a subset of SNPs suggest three main groupings at the level of all studied regions: the Black Sea, the North Atlantic, and the Baltic Sea. Furthermore, we observed a distinct separation of the North Sea harbor porpoises from the Baltic Sea populations, and identified splits between porpoise populations within the Baltic Sea. We observed a notable distinction between the Belt Sea and the Inner Baltic Sea sub-regions. Improved delineation of harbor porpoise population assignments for the Baltic based on genomic evidence is important for conservation management of this endangered cetacean in threatened habitats, particularly in the Baltic Sea proper. In addition, we show that SNPs outperform microsatellite markers and demonstrate the utility of RAD-tags from a relatively small, opportunistically sampled cetacean sample set for population diversity and divergence analysis.
The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs’ embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess–as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., arα/arβ, erα/erβ1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, erβ1 was expressed neither in brain nor in gill in the analyzed three molly species, which implies a more important role of erα in the estradiol synthesis pathway in these tissues. Furthermore, our data suggest that interactions of steroid-signaling pathway genes differ across tissues, in particular the interactions of ars and cyp19as.
Arabidopsis FORGETTER1 mediates stress-induced chromatin memory through nucleosome remodeling
(2016)
Plants as sessile organisms can adapt to environmental stress to mitigate its adverse effects. As part of such adaptation they maintain an active memory of heat stress for several days that promotes a more efficient response to recurring stress. We show that this heat stress memory requires the activity of the FORGETTER1 (FGT1) locus, with fgt1 mutants displaying reduced maintenance of heat-induced gene expression. FGT1 encodes the Arabidopsis thaliana orthologue of Strawberry notch (Sno), and the protein globally associates with the promoter regions of actively expressed genes in a heat-dependent fashion. FGT1 interacts with chromatin remodelers of the SWI/ SNF and ISWI families, which also display reduced heat stress memory. Genomic targets of the BRM remodeler overlap significantly with FGT1 targets. Accordingly, nucleosome dynamics at loci with altered maintenance of heat-induced expression are affected in fgt1. Together, our results suggest that by modulating nucleosome occupancy, FGT1 mediates stress-induced chromatin memory.
When sampling animal movement paths, the frequency at which location measurements are attempted is a critical feature for data analysis. Important quantities derived from raw data, e.g. travel distance or sinuosity, can differ largely based on the temporal resolution of the data. Likewise, when movement models are fitted to data, parameter estimates have been demonstrated to vary with sampling rate. Thus, biological statements derived from such analyses can only be made with respect to the resolution of the underlying data, limiting extrapolation of results and comparison between studies. To address this problem, we investigate whether there are models that are robust against changes in temporal resolution. First, we propose a mathematically rigorous framework, in which we formally define robustness as a model property. We then use the framework for a thorough assessment of a range of basic random walk models, in which we also show how robustness relates to other probabilistic concepts. While we found robustness to be a strong condition met by few models only, we suggest a new method to extend models so as to make them robust. Our framework provides a new systematic, mathematically founded approach to the question if, and how, sampling rate of movement paths affects statistical inference.
African weakly-electric fishes (Mormyridae) are able to communicate through species-specific electric signals; this feature might have favoured the evolutionary radiation observed in this family (over 200 species) by acting as an effective pre-zygotic isolation mechanism. In the present study we used mitochondria((cytb) and nuclear (rps7, scn4aa) markers in order to reconstruct a species-phylogeny and identify species boundaries for the genus Campylomormyrus, by applying inference methods based on the multispecies coalescent model. Additionally, we employed 16 microsatellite markers, landmark-based morphometric measurements, and electro-physiological analyses as independent lines of evidence to the results obtained from the sequence data. The results show that groups that are morphologically different are also significantly divergent at the genetic level, whereas morphologically similar groups, displaying dissimilar electric signals, do not show enough genetic diversity to be considered separate species. Furthermore, the data confirm the presence of a yet undescribed species within the genus Campylomormyrus. (C) 2016 Elsevier Inc. All rights reserved.
Voltage-gated sodium channels, Nav1, play a crucial role in the generation and propagation of action potentials and substantially contribute to the shape of their rising phase. The electric organ discharge (EOD) of African weakly electric fish (Mormyroidea) is the sum of action potentials fired from all electrocytes of the electric organ at the same time and hence voltage-gated sodium channels are one factor—together with the electrocyte’s morphology and innervation pattern—that determines the properties of these EODs. Due to the fish-specific genome duplication, teleost fish possess eight copies of sodium channel genes (SCN), which encode for Nav1 channels. In mormyroids, SCN4aa is solely expressed in the electrocytes of the adult electric organ. In this study, we compared entire SCN4aa sequences of six species of the genus Campylomormyrus and identified nonsynonymous substitutions among them. SCN4aa in Campylomormyrus exhibits a much higher evolutionary rate compared to its paralog SCN4ab, whose expression is not restricted to the electric organ. We also found evidence for strong positive selection on the SCN4aa gene within Mormyridae and along the lineage ancestral to the Mormyridae. We have identified sites at which all nonelectric teleosts are monomorphic in their amino acid, but mormyrids have different amino acids. Our findings confirm the crucial role of SCN4aa in EOD evolution among mormyrid weakly electric fish. The inferred positive selection within Mormyridae makes this gene a prime candidate for further investigation of the divergent evolution of pulse-type EODs among closely related species.
Mitochondriopathies often present clinically as multisystemic disorders of primarily high-energy consuming organs. Assembly, turnover, and surveillance of mitochondrial proteins are essential for mitochondrial function and a key task of AAA family members of metalloproteases. We identified a homozygous mutation in the nuclear encoded mitochondrial escape 1-like 1 gene YME1L1, member of the AAA protease family, as a cause of a novel mitochondriopathy in a consanguineous pedigree of Saudi Arabian descent. The homozygous missense mutation, located in a highly conserved region in the mitochondrial pre-sequence, inhibits cleavage of YME1L1 by the mitochondrial processing peptidase, which culminates in the rapid degradation of YME1L1 precursor protein. Impaired YME1L1 function causes a proliferation defect and mitochondrial network fragmentation due to abnormal processing of OPA1. Our results identify mutations in YME1L1 as a cause of a mitochondriopathy with optic nerve atrophy highlighting the importance of YME1L1 for mitochondrial functionality in humans.
The Dictyostelium centrosome is a model for acentriolar centrosomes and it consists of a three-layered core structure surrounded by a corona harboring microtubule nucleation complexes. Its core structure duplicates once per cell cycle at the G2/M transition. Through proteomic analysis of isolated centrosomes we have identified CP91, a 91-kDa coiled coil protein that was localized at the centrosomal core structure. While GFP-CP91 showed almost no mobility in FRAP experiments during interphase, both GFP-CP91 and endogenous CP91 dissociated during mitosis and were absent from spindle poles from late prophase to anaphase. Since this behavior correlates with the disappearance of the central layer upon centrosome duplication, CP91 is a putative component of this layer. When expressed as GFP-fusions, CP91 fragments corresponding to the central coiled coil domain and the preceding N-terminal part (GFP-CP91cc and GFP-CP91N, respectively) also localized to the centrosome but did not show the mitotic redistribution of the full length protein suggesting a regulatory role of the C-terminal domain. Expression of all GFP-fusion proteins suppressed expression of endogenous CP91 and elicited supernumerary centrosomes. This was also very prominent upon depletion of CP91 by RNAi. Additionally, CP91-RNAi cells exhibited heavily increased ploidy due to severe defects in chromosome segregation along with increased cell size and defects in the abscission process during cytokinesis. Our results indicate that CP91 is a central centrosomal core component required for centrosomal integrity, proper centrosome biogenesis and, independently, for abscission during cytokinesis. (c) 2016 Elsevier GmbH. All rights reserved.
Src1 is a Protein of the Inner Nuclear Membrane Interacting with the Dictyostelium Lamin NE81
(2016)
The nuclear envelope (NE) consists of the outer and inner nuclear membrane (INM), whereby the latter is bound to the nuclear lamina. Src1 is a Dictyostelium homologue of the helix-extension-helix family of proteins, which also includes the human lamin-binding protein MAN1. Both endogenous Src1 and GFP-Src1 are localized to the NE during the entire cell cycle. Immuno-electron microscopy and light microscopy after differential detergent treatment indicated that Src1 resides in the INM. FRAP experiments with GFP-Src1 cells suggested that at least a fraction of the protein could be stably engaged in forming the nuclear lamina together with the Dictyostelium lamin NE81. Both a BioID proximity assay and mis-localization of soluble, truncated mRFP-Src1 at cytosolic clusters consisting of an intentionally mis-localized mutant of GFP-NE81 confirmed an interaction of Src1 and NE81. Expression GFP-Src11–646, a fragment C-terminally truncated after the first transmembrane domain, disrupted interaction of nuclear membranes with the nuclear lamina, as cells formed protrusions of the NE that were dependent on cytoskeletal pulling forces. Protrusions were dependent on intact microtubules but not actin filaments. Our results indicate that Src1 is required for integrity of the NE and highlight Dictyostelium as a promising model for the evolution of nuclear architecture.
Src1 is a Protein of the Inner Nuclear Membrane Interacting with the Dictyostelium Lamin NE81
(2016)
The nuclear envelope (NE) consists of the outer and inner nuclear membrane (INM), whereby the latter is bound to the nuclear lamina. Src1 is a Dictyostelium homologue of the helix-extension-helix family of proteins, which also includes the human lamin-binding protein MAN1. Both endogenous Src1 and GFP-Src1 are localized to the NE during the entire cell cycle. Immuno-electron microscopy and light microscopy after differential detergent treatment indicated that Src1 resides in the INM. FRAP experiments with GFP-Src1 cells suggested that at least a fraction of the protein could be stably engaged in forming the nuclear lamina together with the Dictyostelium lamin NE81. Both a BioID proximity assay and mis-localization of soluble, truncated mRFP-Src1 at cytosolic clusters consisting of an intentionally mis-localized mutant of GFP-NE81 confirmed an interaction of Src1 and NE81. Expression GFP-Src11–646, a fragment C-terminally truncated after the first transmembrane domain, disrupted interaction of nuclear membranes with the nuclear lamina, as cells formed protrusions of the NE that were dependent on cytoskeletal pulling forces. Protrusions were dependent on intact microtubules but not actin filaments. Our results indicate that Src1 is required for integrity of the NE and highlight Dictyostelium as a promising model for the evolution of nuclear architecture.
Engineered nanogels are of high value for a targeted and controlled transport of compounds due to the ability to change their chemical properties by external stimuli. As it has been indicated that nanogels possess a high ability to penetrate the stratum corneum, it cannot be excluded that nanogels interact with dermal dendritic cells, especially in diseased skin. In this study the potential crosstalk of the thermore-sponsive nanogels (tNGs) with the dendritic cells of the skin was investigated with the aim to determine the immunotoxicological properties of the nanogels. The investigated tNGs were made of dendritic polyglycerol (dPG) and poly(glycidyl methyl ether-co-ethyl glycidyl ether) (p(GME-co-EGE)), as polymer conferring thermoresponsive properties. Although the tNGs were taken up, they displayed neither cytotoxic and genotoxic effects nor any induction of reactive oxygen species in the tested cells. Interestingly, specific uptake mechanisms of the tNGs by the dendritic cells were depending on the nanogels cloud point temperature (Tcp), which determines the phase transition of the nanoparticle. The study points to caveolae-mediated endocytosis as being the major tNGs uptake mechanism at 37 degrees C, which is above the Tcp of the tNGs. Remarkably, an additional uptake mechanism, beside caveolae-mediated endocytosis, was observed at 29 degrees C, which is the Tcp of the tNGs. At this temperature, which is characterized by two different states of the tNGs, macropinocytosis was involved as well. In summary, our study highlights the impact of thermoresponsivity on the cellular uptake mechanisms which has to be taken into account if the tNGs are used as a drug delivery system.
Aims Plants directly and indirectly interact with many abiotic and biotic soil components. Research so far mostly focused on direct, individual abiotic or biotic effects on plant growth, but only few studies tested the indirect effects of abiotic soil factors on plant growth. Therefore, we investigated how abiotic soil conditions affect plant performance, via changes induced by soil biota. Methods In a full-factorial experiment, we grew the widespread grass Dactylis glomerata either with or without soil biota and investigated the impact of soil temperature, fertility and moisture on the soil biota effects on plant growth. We measured biomass production, root traits and colonization by arbuscular mycorrhizal fungi as well as microbial respiration. Important Findings We found significant interaction effects between abiotic soil conditions and soil biota on plant growth for fertility, but especially for soil temperature, as an increase of 10 degrees C significantly changed the soil biota effects on plant growth from positive to neutral. However, if tested individually, an increase in soil temperature and fertility per se positively affected plant biomass production, whereas soil biota per se did not affect overall plant growth, but both influenced root architecture. By affecting soil microbial activity and root architecture, soil temperature might influence both mutualistic and pathogenic interactions between plants and soil biota. Such soil temperature effects should be considered in soil feedback studies to ensure greater transferability of results from artificial and experimental conditions to natural environmental conditions.
We compiled global occurrence data sets of 13 congeneric sexual and apomictic species pairs, and used principal components analysis (PCA) and kernel smoothers to compare changes in climatic niche optima, breadths and unfilling/expansion between native and alien ranges. Niche change metrics were compared between sexual and apomictic species. All 26 species showed changes in niche optima and/or breadth and 14 species significantly expanded their climatic niches. However, we found no effect of the reproductive system on niche dynamics. Instead, species with narrower native niches showed higher rates of niche expansion in the alien ranges. Our results suggest that niche shifts are frequent in plant invasions but evolutionary potential may not be of major importance for such shifts. Niche dynamics rather appear to be driven by changes of the realized niche without adaptive change of the fundamental climatic niche.
In nature, plants often encounter chronic or recurring stressful conditions. Recent results indicate that plants can remember a past exposure to stress to be better prepared for a future stress incident. However, the molecular basis of this is poorly understood. Here, we report the involvement of chromatin modifications in the maintenance of acquired thermotolerance (heat stress [HS] memory). HS memory is associated with the accumulation of histone H3 lysine 4 di- and trimethylation at memory-related loci. This accumulation outlasts their transcriptional activity and marks them as recently transcriptionally active. High accumulation of H3K4 methylation is associated with hyper-induction of gene expression upon a recurring HS. This transcriptional memory and the sustained accumulation of H3K4 methylation depend on HSFA2, a transcription factor that is required for HS memory, but not initial heat responses. Interestingly, HSFA2 associates with memory-related loci transiently during the early stages following HS. In summary, we show that transcriptional memory after HS is associated with sustained H3K4 hyper-methylation and depends on a hit-and-run transcription factor, thus providing a molecular framework for HS memory.
SUBJECTS/METHODS: The study included 5597 boys and 5479 girls aged 7-8 years of age. Socioeconomic status (SES) was defined in three categories: high, medium and low. RESULTS: Between 1966 and 2012, the mean values for height and BMI significantly increased in both sexes (P<0.001). The variation of these two parameters, however, showed a different pattern. Whereas the variation in Z-values for height remained unchanged in both sexes, the variation in BMI increased in boys (P<0.01) but not in girls. SES affected the variation in Z-BMI in 1978 in both sexes (P<0.001), whereas variation in Z-height between SES categories remained unchanged across all years of surveys in boys. Before the political transformation, significant regional differences were observed in the variances of Z-BMI (P<0.05) but not of Z-height. This pattern changed after the political transformation, when regional differences in variances of Z-BMI disappeared. CONCLUSIONS: It is concluded that the mean values and the variation of BMI are affected by a changing quality of life, whereas the variation in height is usually independent of living conditions.
We tested the influence of two light intensities [40 and 300 μmol PAR / (m2s)] on the fatty acid composition of three distinct lipid classes in four freshwater phytoplankton species. We chose species of different taxonomic classes in order to detect potentially similar reaction characteristics that might also be present in natural phytoplankton communities. From samples of the bacillariophyte Asterionella formosa, the chrysophyte Chromulina sp., the cryptophyte Cryptomonas ovata and the zygnematophyte Cosmarium botrytis we first separated glycolipids (monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol), phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine) as well as non-polar lipids (triacylglycerols), before analyzing the fatty acid composition of each lipid class. High variation in the fatty acid composition existed among different species. Individual fatty acid compositions differed in their reaction to changing light intensities in the four species. Although no generalizations could be made for species across taxonomic classes, individual species showed clear but small responses in their ecologically-relevant omega-3 and omega-6 polyunsaturated fatty acids (PUFA) in terms of proportions and of per tissue carbon quotas. Knowledge on how lipids like fatty acids change with environmental or culture conditions is of great interest in ecological food web studies, aquaculture, and biotechnology, since algal lipids are the most important sources of omega-3 long-chain PUFA for aquatic and terrestrial consumers, including humans.
Organism growth can be limited either by a single resource or by multiple resources simultaneously (co-limitation). Efforts to characterise co-limitation have generated two influential approaches. One approach uses limitation scenarios of factorial growth assays to distinguish specific types of co-limitation; the other uses growth responses spanned over a continuous, multi-dimensional resource space to characterise different types of response surfaces. Both approaches have been useful in investigating particular aspects of co-limitation, but a synthesis is needed to stimulate development of this recent research area. We address this gap by integrating the two approaches, thereby presenting a more general framework of co-limitation. We found that various factorial (co-)limitation scenarios can emerge in different response surface types based on continuous availabilities of essential or substitutable resources. We tested our conceptual co-limitation framework on data sets of published and unpublished studies examining the limitation of two herbivorous consumers in a two-dimensional resource space. The experimental data corroborate the predictions, suggesting a general applicability of our co-limitation framework to generalist consumers and potentially also to other organisms. The presented framework might give insight into mechanisms that underlie co-limitation responses and thus can be a seminal starting point for evaluating co-limitation patterns in experiments and nature.
Understanding animal performance in heterogeneous or variable environments is a central question in ecology. We combine modelling and experiments to test how temperature and food availability variance jointly affect life-history traits of ectotherms. The model predicts that as mean temperatures move away from the ectotherm's thermal optimum, the effect size of joint thermal and food variance should become increasingly sensitive to their covariance. Below the thermal optimum, performance should be positively correlated with food–temperature covariance and the opposite is predicted above it. At lower temperatures, covariance should determine whether food and temperature variance increases or decreases performance compared to constant conditions. Somewhat stronger than predicted, the covariance effect below the thermal optimum was confirmed experimentally on an aquatic ectotherm (Daphnia magna) exposed to diurnal food and temperature variance with different amounts of covariance. Our findings have important implications for understanding ectotherm responses to climate-driven alterations of thermal mean and variance.