Understanding how species assemble into communities is a key goal in ecology. However, assembly rules are rarely tested experimentally, and their ability to shape real communities is poorly known. We surveyed a diverse community of epiphyte-dwelling ants and found that similar-sized species co-occurred less often than expected. Laboratory experiments demonstrated that invasion was discouraged by the presence of similarly sized resident species. The size difference for which invasion was less likely was the same as that for which wild species exhibited reduced co-occurrence. Finally we explored whether our experimentally derived assembly rules could simulate realistic communities. Communities simulated using size-based species assembly exhibited diversities closer to wild communities than those simulated using size-independent assembly, with results being sensitive to the combination of rules employed. Hence, species segregation in the wild can be driven by competitive species assembly, and this process is sufficient to generate observed species abundance distributions for tropical epiphyte-dwelling ants.

• MeSH
• biologické modely * MeSH
• Formicidae * MeSH
• kompetitivní chování MeSH
• společenstvo * MeSH
• symbióza MeSH
• zavlečené druhy * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Borneo MeSH

• MeSH
• integrovaná výuka MeSH
• lidé MeSH
• pomůcky pro sebeobsluhu MeSH
• postižení * rehabilitace   výchova   zákonodárství a právo   MeSH
• sociální péče MeSH
• sociální zabezpečení MeSH
• zaměstnání pro postižené MeSH
• zdravotní služby pro osoby s postižením MeSH
• Check Tag
• lidé MeSH
• Geografické názvy
• Španělsko MeSH

BACKGROUND: Alternative organism designs (i.e. the existence of distinct combinations of traits leading to the same function or performance) are a widespread phenomenon in nature and are considered an important mechanism driving the evolution and maintenance of species trait diversity. However, alternative designs are rarely considered when investigating assembly rules and species effects on ecosystem functioning, assuming that single trait trade-offs linearly affect species fitness and niche differentiation. SCOPE: Here, we first review the concept of alternative designs, and the empirical evidence in plants indicating the importance of the complex effects of multiple traits on fitness. We then discuss how the potential decoupling of single traits from performance and function of species can compromise our ability to detect the mechanisms responsible for species coexistence and the effects of species on ecosystems. Placing traits in the continuum of organism integration level (i.e. traits hierarchically structured ranging from organ-level traits to whole-organism traits) can help in choosing traits more directly related to performance and function. CONCLUSIONS: We conclude that alternative designs have important implications for the resulting trait patterning expected from different assembly processes. For instance, when only single trade-offs are considered, environmental filtering is expected to result in decreased functional diversity. Alternatively, it may result in increased functional diversity as an outcome of alternative strategies providing different solutions to local conditions and thus supporting coexistence. Additionally, alternative designs can result in higher stability of ecosystem functioning as species filtering due to environmental changes would not result in directional changes in (effect) trait values. Assessing the combined effects of multiple plant traits and their implications for plant functioning and functions will improve our mechanistic inferences about the functional significance of community trait patterning.

• MeSH
• biodiverzita MeSH
• ekosystém * MeSH
• fenotyp MeSH
• fyziologie rostlin MeSH
• rostliny * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Glucose oxidase (GOX) is a homodimeric glycoprotein with tightly bound one molecule of FAD cofactor per monomer of the protein. GOX has numerous applications, but the preparation of biotechnologically interesting GOX sensors requires a removal of the native FAD cofactor. This process often leads to unwanted irreversible deflavination and, as a consequence, to the low enzyme recovery. Molecular mechanisms of reversible reflavination are poorly understood; our current knowledge is based only on empiric rules, which is clearly insufficient for further development. To develop conceptual understanding of flavin-binding competent states, we studied the effect of deflavination protocols on conformational properties of GOX. After deflavination, the apoform assembles into soluble oligomers with nearly native-like holoform secondary structure but largely destabilized tertiary structure presumambly due to the packing density defects around the vacant flavin binding site. The reflavination is cooperative but not fully efficient; after the binding the flavin cofactor, the protein directly disassembles into native homodimers while the fraction of oligomers remains irreversibly inactivated. Importantly, the effect of Hofmeister salts on the conformational properties of GOX and reflavination efficiency indicates that the native-like residual tertiary structure in the molten-globule states favorably supports the reflavination and minimizes the inactivated oligomers. We interpret our results by combining the ligand-induced changes in quaternary structure with salt-sensitive, non-equilibrated conformational selection model. In summary, our work provides the very first steps toward molecular understanding the complexity of the GOX reflavination mechanism.

• MeSH
• Aspergillus niger enzymologie   MeSH
• biokatalýza MeSH
• cirkulární dichroismus MeSH
• diferenciální skenovací kalorimetrie MeSH
• flavinadenindinukleotid chemie   metabolismus   MeSH
• glukosaoxidasa chemie   metabolismus   MeSH
• multimerizace proteinu MeSH
• protein - isoformy chemie   metabolismus   MeSH
• sekundární struktura proteinů MeSH
• spektrofotometrie ultrafialová MeSH
• stabilita proteinů MeSH
• teplota MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• integrace do komunity MeSH
• postižení zákonodárství a právo   MeSH
• veřejná politika MeSH
• Publikační typ
• souborné dílo MeSH

• Konspekt
• Pracovní, sociální, stavební právo. Právo životního prostředí
• NLK Obory
• právo, zákonodárství
• zdravotně postižení
• NLK Publikační typ
• semináře

UNLABELLED: The pollination services provided by the western honeybee (Apis mellifera) are critical for agricultural production and the diversity of wild flowering plants. However, honeybees suffer from environmental pollution, habitat loss, and pathogens, including viruses that can cause fatal diseases. Israeli acute bee paralysis virus (IAPV), from the family Dicistroviridae, has been shown to cause colony collapse disorder in the United States. Here, we present the IAPV virion structure determined to a resolution of 4.0 Å and the structure of a pentamer of capsid protein protomers at a resolution of 2.7 Å. IAPV has major capsid proteins VP1 and VP3 with noncanonical jellyroll β-barrel folds composed of only seven instead of eight β-strands, as is the rule for proteins of other viruses with the same fold. The maturation of dicistroviruses is connected to the cleavage of precursor capsid protein VP0 into subunits VP3 and VP4. We show that a putative catalytic site formed by the residues Asp-Asp-Phe of VP1 is optimally positioned to perform the cleavage. Furthermore, unlike many picornaviruses, IAPV does not contain a hydrophobic pocket in capsid protein VP1 that could be targeted by capsid-binding antiviral compounds. IMPORTANCE: Honeybee pollination is required for agricultural production and to sustain the biodiversity of wild flora. However, honeybee populations in Europe and North America are under pressure from pathogens, including viruses that cause colony losses. Viruses from the family Dicistroviridae can cause honeybee infections that are lethal, not only to individual honeybees, but to whole colonies. Here, we present the virion structure of an Aparavirus, Israeli acute bee paralysis virus (IAPV), a member of a complex of closely related viruses that are distributed worldwide. IAPV exhibits unique structural features not observed in other picorna-like viruses. Capsid protein VP1 of IAPV does not contain a hydrophobic pocket, implying that capsid-binding antiviral compounds that can prevent the replication of vertebrate picornaviruses may be ineffective against honeybee virus infections.

• MeSH
• Dicistroviridae ultrastruktura   MeSH
• konformace proteinů MeSH
• krystalografie rentgenová MeSH
• molekulární modely MeSH
• multimerizace proteinu MeSH
• včely virologie   MeSH
• virion ultrastruktura   MeSH
• virové plášťové proteiny chemie   metabolismus   MeSH
• virové struktury * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• angličtina,
• MeSH
• lingvistika MeSH
• Publikační typ
• učebnice MeSH

• Konspekt
• Všeobecná příručková díla
• NLK Obory
• všeobecná příručková díla a encyklopedie
• věda a výzkum

• MeSH
• lingvistika MeSH
• Publikační typ
• učebnice MeSH

• Konspekt
• Lingvistika. Jazyky
• NLK Obory
• lingvistika, lékařská terminologie

The community composition of any group of organisms should theoretically be determined by a combination of assembly processes including resource partitioning, competition, environmental filtering, and phylogenetic legacy. Environmental DNA studies have revealed a huge diversity of protists in all environments, raising questions about the ecological significance of such diversity and the degree to which they obey to the same rules as macroscopic organisms. The fast-growing cultivable protist species on which hypotheses are usually experimentally tested represent only a minority of the protist diversity. Addressing these questions for the lesser known majority can only be inferred through observational studies. We conducted an environmental DNA survey of the genus Nebela, a group of closely related testate (shelled) amoeba species, in different habitats within Sphagnum-dominated peatlands. Identification based on the mitochondrial cytochrome c oxidase 1 gene, allowed species-level resolution as well as phylogenetic reconstruction. Community composition varied strongly across habitats and associated environmental gradients. Species showed little overlap in their realized niche, suggesting resource partitioning, and a strong influence of environmental filtering driving community composition. Furthermore, phylogenetic clustering was observed in the most nitrogen-poor samples, supporting phylogenetic inheritance of adaptations in the group of N. guttata. This study showed that the studied free-living unicellular eukaryotes follow to community assembly rules similar to those known to determine plant and animal communities; the same may be true for much of the huge functional and taxonomic diversity of protists.

• MeSH
• ekologie MeSH
• ekosystém * MeSH
• fylogeneze MeSH
• rašeliníky * MeSH
• rostliny MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The known ubiquitous presence of glycans fulfils an essential prerequisite for fundamental roles in cell sociology. Since carbohydrates are chemically predestined to form biochemical messages of a maximum of structural diversity in a minimum of space, coding of biological information by sugars is the reason for the broad occurrence of cellular glycoconjugates. Their glycans originate from sophisticated enzymatic assembly and dynamically adaptable remodelling. These signals are read and translated into effects by receptors (lectins). The functional pairing between lectins and their counterreceptor(s) is highly specific, often orchestrated by intimate co-regulation of the receptor, the cognate glycan and the bioactive scaffold (e.g., an integrin). Bottom-up approaches, teaming up synthetic and supramolecular chemistry to prepare fully programmable nanoparticles as binding partners with systematic network analysis of lectins and rational design of variants, enable us to delineate the rules of the sugar code.

• MeSH
• lektiny metabolismus   MeSH
• lidé MeSH
• polysacharidy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH