BACKGROUND: Emergence of both viral zoonoses from bats and diseases that threaten bat populations has highlighted the necessity for greater insights into the functioning of the bat immune system. Particularly when considering hibernating temperate bat species, it is important to understand the seasonal dynamics associated with immune response. Body temperature is one of the factors that modulates immune functions and defence mechanisms against pathogenic agents in vertebrates. To better understand innate immunity mediated by phagocytes in bats, we measured respiratory burst and haematology and blood chemistry parameters in heterothermic greater mouse-eared bats (Myotis myotis) and noctules (Nyctalus noctula) and homeothermic laboratory mice (Mus musculus). RESULTS: Bats displayed similar electrolyte levels and time-related parameters of phagocyte activity, but differed in blood profile parameters related to metabolism and red blood cell count. Greater mouse-eared bats differed from mice in all phagocyte activity parameters and had the lowest phagocytic activity overall, while noctules had the same quantitative phagocytic values as mice. Homeothermic mice were clustered separately in a high phagocyte activity group, while both heterothermic bat species were mixed in two lower phagocyte activity clusters. Stepwise regression identified glucose, white blood cell count, haemoglobin, total dissolved carbon dioxide and chloride variables as the best predictors of phagocyte activity. White blood cell counts, representing phagocyte numbers available for respiratory burst, were the best predictors of both time-related and quantitative parameters of phagocyte activity. Haemoglobin, as a proxy variable for oxygen available for uptake by phagocytes, was important for the onset of phagocytosis. CONCLUSIONS: Our comparative data indicate that phagocyte activity reflects the physiological state and blood metabolic and cellular characteristics of homeothermic and heterothermic mammals. However, further studies elucidating trade-offs between immune defence, seasonal lifestyle physiology, hibernation behaviour, roosting ecology and geographic patterns of immunity of heterothermic bat species will be necessary. An improved understanding of bat immune responses will have positive ramifications for wildlife and conservation medicine.
- MeSH
- biochemická analýza krve MeSH
- Chiroptera krev imunologie MeSH
- chování zvířat fyziologie MeSH
- fagocyty imunologie MeSH
- počet erytrocytů MeSH
- tělesná teplota * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
It has been hypothesized that species with holocentric chromosomes have a selective evolutionary advantage for developmental and reproductive success because holocentric chromosomes are less susceptible to chromosome breakage than monocentric chromosomes. We analyzed data on sterilizing doses of ionizing radiation for more than 250 species of arthropods to test whether the minimal dose for reproductive sterilization is higher for species with holocentric chromosomes than for species with monocentric chromosomes. Using linear mixed models that account for phylogeny, we show that holocentric arthropods are more tolerant of sterilizing radiation than monocentrics. Moreover, higher dose rates correlate with lower sterilizing doses in monocentrics, but not in holocentrics, which is a novel finding that may be of importance for radiosanitation practice. Under the dose rate of 1 Gy/min, holocentric arthropods are sterilized on average with a 2.9 times higher minimal dose than monocentrics. Life stage and sex have significant but considerably weaker effects on sterilizing dose than chromosome type. Adults and males require 1.2 and 1.4 times higher sterilizing doses than juveniles and females, respectively. These results support the hypothesis that holocentric lineages may originate and thrive better in times of increased exposure to chromosome-breaking factors.
Feathers gradually accumulate hormones and reflect long-term average plasma steroid levels during their growth. Feather hormone levels thus provide for the measurement of plasma hormones concentrations integrated over a period of several days or weeks. In this study, we focused on the development of a method to determine testosterone (TEST) and corticosterone (CORT) levels in extracts from feathers of small bodied birds with a limited amount of feathers available per individual. For this purpose, the method had to be verified for a small weight of samples. The present study describes the effect of the conditions of sample preparation and keto-derivatisation on the sensitivity of the LC-ESI-MS/MS analysis of TEST and CORT. Generally, chemical derivatization improves the sensitivity and selectivity of LC-MS/MS analysis. It can be used particularly in situations when the total amount of collected sample is limited (such as in our studies). Both the conditions of feather sample preparation (the selection of the extraction solvent, the time of extraction, and the conditions of solid phase extraction) and the reaction conditions affecting the formation of keto-derivatives (such as reaction temperature and reaction time) were tested. Methanol as the extraction solvent, 8 h as the extraction time, 50 °C as the reaction temperature of derivatization, and 90 min as the reaction time of derivatization are the most suitable conditions in terms of achieving a high sensitivity of analyses. Calibration curves are linear, at least in the range 25-2500 pg mL-1, which is usually found in feather extracts. The limit of detection (LOD) for TEST and CORT was 1.0 and 0.3 pg per mL, respectively. The limit of quantification (LOQ) for TEST and CORT was 3.3 and 1.0 pg per mL, respectively. The optimized procedure was successfully applied for the analysis of TEST and CORT in real feather samples. The method could be used in a variety of research direction including wildlife, agricultural or veterinary studies.
- MeSH
- chromatografie kapalinová metody MeSH
- hmotnostní spektrometrie metody MeSH
- kortikosteron analýza MeSH
- peří chemie MeSH
- ptáci MeSH
- testosteron analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The search for traits associated with plant invasiveness has yielded contradictory results, in part because most previous studies have failed to recognize that different traits are important at different stages along the introduction-naturalization-invasion continuum. Here we show that across six different habitat types in temperate Central Europe, naturalized non-invasive species are functionally similar to native species occurring in the same habitat type, but invasive species are different as they occupy the edge of the plant functional trait space represented in each habitat. This pattern was driven mainly by the greater average height of invasive species. These results suggest that the primary determinant of successful establishment of alien species in resident plant communities is environmental filtering, which is expressed in similar trait distributions. However, to become invasive, established alien species need to be different enough to occupy novel niche space, i.e. the edge of trait space.
- MeSH
- druhová specificita MeSH
- ekologie MeSH
- ekosystém * MeSH
- fenotyp MeSH
- fylogeneze MeSH
- fyziologie rostlin * MeSH
- rostliny klasifikace MeSH
- vývoj rostlin MeSH
- zavlečené druhy * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Animals self-medicate using a variety of plant and arthropod secondary metabolites by either ingesting them or anointing them to their fur or skin apparently to repel ectoparasites and treat skin diseases. In this respect, much attention has been focused on primates. Direct evidence for self-medication among the great apes has been limited to Africa. Here we document self-medication in the only Asian great ape, orang-utans (Pongo pygmaeus), and for the first time, to our knowledge, the external application of an anti-inflammatory agent in animals. The use of leaf extracts from Dracaena cantleyi by orang-utan has been observed on several occasions; rubbing a foamy mixture of saliva and leaf onto specific parts of the body. Interestingly, the local indigenous human population also use a poultice of these leaves for the relief of body pains. We present pharmacological analyses of the leaf extracts from this species, showing that they inhibit TNFα-induced inflammatory cytokine production (E-selectin, ICAM-1, VCAM-1 and IL-6). This validates the topical anti-inflammatory properties of this plant and provides a possible function for its use by orang-utans. This is the first evidence for the deliberate external application of substances with demonstrated bioactive potential for self-medication in great apes.
- MeSH
- biologické markery MeSH
- biologické přípravky * chemie farmakologie MeSH
- buněčné linie MeSH
- chování zvířat * MeSH
- cytokiny metabolismus MeSH
- Dracaena chemie metabolismus MeSH
- endoteliální buňky účinky léků metabolismus MeSH
- léčivé rostliny * MeSH
- lidé MeSH
- mediátory zánětu metabolismus MeSH
- Pongo pygmaeus * MeSH
- rostlinné extrakty chemie farmakologie MeSH
- samoléčba * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The common bed bug Cimex lectularius, has been recently shown to constitute two host races, which are likely in the course of incipient speciation. The human-associated lineage splits from the ancestral bat-associated species deep in the history of modern humans, likely even prior to the Neolithic Period and establishment of the first permanent human settlements. Hybridization experiments between these two lineages show that post-mating reproductive barriers are incomplete due to local variation. As mating takes place in off-host refugia marked by aggregation semiochemicals, the present investigation tested the hypothesis that bed bugs use these semiochemicals to differentiate between refugia marked by bat- and human-associated bed bugs; this would constitute a pre-copulation isolation mechanism. The preference for lineage-specific odors was tested using artificial shelters conditioned by a group of either male or female bed bugs. Adult males were assayed individually in four-choice assays that included two clean unconditioned control shelters. In most assays, bed bugs preferred to rest in conditioned shelters, with no apparent fidelity to shelters conditioned by their specific lineage. However, 51 % of the bat-associated males preferred unconditioned shelters over female-conditioned shelters of either lineage. Thus, bed bugs show no preferences for lineage-specific shelters, strongly suggesting that semiochemicals associated with shelters alone do not function in reproductive isolation.
- MeSH
- biotest MeSH
- Chiroptera parazitologie MeSH
- hybridizace genetická MeSH
- infestace ektoparazity parazitologie veterinární MeSH
- lidé MeSH
- odoranty analýza MeSH
- rozmnožování MeSH
- štěnice klasifikace genetika fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Fungi represent a group of soil microorganisms fulfilling important ecological functions. Although several studies have shown that yeasts represent a significant proportion of fungal communities, our current knowledge is based mainly on cultivation experiments. In this study, we used amplicon sequencing of environmental DNA to describe the composition of yeast communities in European temperate forest and to identify the potential biotic and abiotic drivers of community assembly. Based on the analysis of ITS2 PCR amplicons, yeasts represented a substantial proportion of fungal communities ranging from 0.4 to 14.3% of fungal sequences in soil and 0.2 to 9.9% in litter. The species richness at individual sites was 28 ± 9 in soil and 31 ± 11 in litter. The basidiomycetous yeasts dominated over ascomycetous ones. In litter, yeast communities differed significantly among beech-, oak- and spruce-dominated stands. Drivers of community assembly are probably more complex in soils and comprise the effects of environmental conditions and vegetation.
Ecological studies of peatland testate amoebae are generally based on totals of 150 individuals per sample. However, the suitability of this standard has never been assessed for alkaline habitats such as spring fens. We explored the differences in testate amoeba diversity between Sphagnum and brown-moss microhabitats at a mire site with a highly diversified moss layer which reflects the small-scale heterogeneity in groundwater chemistry. Relationships between sampling efficiency and sample completeness were explored using individual-based species accumulation curves and the effort required to gain an extra species was assessed. Testate amoeba diversity differed substantially between microhabitats, with brown mosses hosting on average twice as many species and requiring greater shell totals to reach comparable sample analysis efficiency as for Sphagnum. Thus, for samples from alkaline conditions an increase in shell totals would be required and even an overall doubling up to 300 individuals might be considered for reliable community description. Our small-scale data are likely not robust enough to provide an ultimate solution for the optimization of shell totals. However, the results proved that testate amoebae communities from acidic and alkaline environments differ sharply in both species richness and composition and they might call for different methodological approaches.
Excystation of sporozoites of Cryptosporidium parvum from oocysts is essential for successful in vitro assays. It has also been traditionally used as a measure for oocyst viability and infectivity. Laboratories use various excystation protocols so there is a need to clarify which method is the best. In this study, six different protocols for in vitro excystation of C. parvum oocysts were compared to find the most efficient excystation method (expressed as percentage excystation). Tested protocols differed in chemical pre-incubation steps, excystation media or time of incubation. There were significant differences in percentage of excysted oocysts among groups excysted by different methods. There were also significant differences in percentage of excysted oocysts between methods using pre-incubation with sodium hypochlorite and those without. The other variables examined; the presence of trypsin, kind of excystation medium and the incubation time, did not show statistical differences in percentage excystation among groups. Pre-incubation steps which included sodium hypochlorite, enhancing the permeability of the oocysts were found to increase the excystation ratio and methods using this step were the most effective.
- MeSH
- chlornan sodný farmakologie MeSH
- Cryptosporidium parvum účinky léků fyziologie MeSH
- kultivační média farmakologie MeSH
- oocysty účinky léků MeSH
- parazitologie metody MeSH
- permeabilita účinky léků MeSH
- trypsin farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The centromere drive model explaining rapid evolution of eukaryotic centromeres predicts higher frequency of positive selection acting on centromeric histone H3 (CenH3) in clades with asymmetric meiosis compared to the clades with only symmetric meiosis. However, despite the impression one might get from the literature, this key prediction of the centromere drive model has not only never been confirmed, but it has never been tested, because all the previous studies dealt only with the presence or absence instead of the frequency of positive selection. To provide evidence for or against different frequencies of positively selected CenH3 in asymmetrics and symmetrics, we have inferred the selective pressures acting on CenH3 in seventeen eukaryotic clades, including plants, animals, fungi, ciliates and apicomplexa, using codon-substitution models, and compared the inferred frequencies between asymmetrics and symmetrics in a quantitative manner. We have found that CenH3 has been evolving adaptively much more frequently in clades with asymmetric meiosis compared with clades displaying only symmetric meiosis which confirms the prediction of centromere drive model. Our findings indicate that the evolution of asymmetric meiosis required CenH3 to evolve adaptively more often to counterbalance the negative consequences of centromere drive.
- MeSH
- centromera genetika MeSH
- histony genetika MeSH
- houby genetika MeSH
- kodon genetika MeSH
- lidé MeSH
- meióza genetika MeSH
- molekulární evoluce * MeSH
- protein CENP-A genetika MeSH
- rostlinné proteiny genetika MeSH
- sekvenční seřazení MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
