biotic interaction
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Several aerobic bacteria possess unique catabolic pathways enabling them to degrade persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polybrominated diphenylethers (PBDEs), and polychlorinated biphenyls (PCBs). The catabolic activity of aerobic bacteria employed for removal of POPs in the environment may be modulated by several biotic (i.e. fungi, plants, algae, earthworms, and other bacteria) and abiotic (i.e. zero-valent iron, advanced oxidation, and electricity) agents. This review describes the basic biochemistry of the aerobic bacterial catabolism of selected POPs and discusses how biotic and abiotic agents enhance or inhibit the process. Solutions allowing biotic and abiotic agents to exert physical and chemical assistance to aerobic bacterial catabolism of POPs are also discussed.
- MeSH
- aerobní bakterie izolace a purifikace metabolismus MeSH
- látky znečišťující životní prostředí metabolismus MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND: Anaplasma phagocytophilum is currently regarded as a single species. However, molecular studies indicate that it can be subdivided into ecotypes, each with distinct but overlapping transmission cycle. Here, we evaluate the interactions between and within clusters of haplotypes of the bacterium isolated from vertebrates and ticks, using phylogenetic and network-based methods. METHODS: The presence of A. phagocytophilum DNA was determined in ticks and vertebrate tissue samples. A fragment of the groEl gene was amplified and sequenced from qPCR-positive lysates. Additional groEl sequences from ticks and vertebrate reservoirs were obtained from GenBank and through literature searches, resulting in a dataset consisting of 1623 A. phagocytophilum field isolates. Phylogenetic analyses were used to infer clusters of haplotypes and to assess phylogenetic clustering of A. phagocytophilum in vertebrates or ticks. Network-based methods were used to resolve host-vector interactions and their relative importance in the segregating communities of haplotypes. RESULTS: Phylogenetic analyses resulted in 199 haplotypes within eight network-derived clusters, which were allocated to four ecotypes. The interactions of haplotypes between ticks, vertebrates and geographical origin, were visualized and quantified from networks. A high number of haplotypes were recorded in the tick Ixodes ricinus. Communities of A. phagocytophilum recorded from Korea, Japan, Far Eastern Russia, as well as those associated with rodents had no links with the larger set of isolates associated with I. ricinus, suggesting different evolutionary pressures. Rodents appeared to have a range of haplotypes associated with either Ixodes trianguliceps or Ixodes persulcatus and Ixodes pavlovskyi. Haplotypes found in rodents in Russia had low similarities with those recorded in rodents in other regions and shaped separate communities. CONCLUSIONS: The groEl gene fragment of A. phagocytophilum provides information about spatial segregation and associations of haplotypes to particular vector-host interactions. Further research is needed to understand the circulation of this bacterium in the gap between Europe and Asia before the overview of the speciation features of this bacterium is complete. Environmental traits may also play a role in the evolution of A. phagocytophilum in ecotypes through yet unknown relationships.
- MeSH
- Anaplasma phagocytophilum genetika izolace a purifikace MeSH
- chaperon hsp60 genetika MeSH
- ekotyp MeSH
- fylogeneze * MeSH
- haplotypy MeSH
- klíště mikrobiologie MeSH
- molekulární evoluce * MeSH
- obratlovci mikrobiologie MeSH
- společenstvo * MeSH
- zeměpis MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Asie MeSH
- Evropa MeSH
The ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. Despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. We tested several predictions about the joint influence of predator/prey scents and thermal conditions on the plasticity of preferred body temperatures (T (p)) in both actors of this interaction, using a dragonfly nymphs-newt larvae system. Dragonfly nymphs (Aeshna cyanea) and newt eggs (Ichthyosaura alpestris) were subjected to fluctuating cold and warm thermal regimes (7-12 and 12-22°C, respectively) and the presence/absence of a predator or prey chemical cues. Preferred body temperatures were measured in an aquatic thermal gradient (5-33°C) over a 24-h period. Newt T (p) increased with developmental temperature irrespective of the presence/absence of predator cues. In dragonflies, thermal reaction norms for T (p) were affected by the interaction between temperature and prey cues. Specifically, the presence of newt scents in cold regime lowered dragonfly T (p). We concluded that predator-prey interactions influenced thermally-induced plasticity of T (p) but not in a reciprocal fashion. The occurrence of frequency-dependent thermal plasticity may have broad implications for predator-prey population dynamics, the evolution of thermal biology traits, and the consequences of sustaining climate change within ecological communities.
Experimentální i klinická data přinášejí stále více důkazů o existenci interakce mezi nervovým, endokrinním a imunitním systémem. V současnosti bylo nalezeno několik mechanizmů, které se uplatňují při interakci těchto systémů. Nervový systém se může uplatnit při inervaci imunitních orgánů, při sekreci hormonů hypofýzy a jiných endokrinních žláz, a rovněž prostřednictvím vegetativního nervového systému. Naproti tomu buňky imunitního systému se mohou uplatnit sekrecí řady chemických poslů, z nichž největší význam mají cytokiny. Klíčovou úlohu má v uvedených interakcích CRF a jeho receptorové podtypy . Také vysoko- a nízko-afinní receptory pro glukokortikoidy jsou zodpovědné za konečnou sledovanou odpověď, zvláště po stresu a při rozvoji stresem podmíněných chorob. Tento přehled uvádí některé nové hormony a nové látky, které působí jako agonisté a antagonisté na známých podtypech CRF receptorů. Perspektivní jsou především antagonisté nepeptidové povahy, které mají potenciální možnost terapeutického použití u celé řady nemocí, včetně duševních poruch a působení stresu.
Experimental as well as clinical data constantly bring stronger evidence about the nervous, endocrine and immune system interactions. Several mechanisms by which these systems might interact have now been recognized. The nervous system may act on immune system via its innervations, by secretion of hormones by adenohypophysis and other endocrine glands, and also through the influence on the autonomic nervous system. On the other side cells of the immune system are acting through secretion of many chemical messengers; cytokines are the most important. The key role in the mentioned interactions plays CRF and its receptor subtypes. Also low- and high-affinity receptors for glucocorticoids are responsible for the final observed response, mainly after application of stressors and during the development of stress-induced diseases. This review also lists some hormones and new drugs that act as agonists and antagonists on known receptor subtypes for CRF. Perspective are mainly non-peptide antagonists that have potential for the therapeutic use in many diseases, including psychiatric and behavioral disorders.
Decomposition of organic material by soil microbes generates an annual global release of 50-75 Pg carbon to the atmosphere, ∼7.5-9 times that of anthropogenic emissions worldwide. This process is sensitive to global change factors, which can drive carbon cycle-climate feedbacks with the potential to enhance atmospheric warming. Although the effects of interacting global change factors on soil microbial activity have been a widespread ecological focus, the regulatory effects of interspecific interactions are rarely considered in climate feedback studies. We explore the potential of soil animals to mediate microbial responses to warming and nitrogen enrichment within a long-term, field-based global change study. The combination of global change factors alleviated the bottom-up limitations on fungal growth, stimulating enzyme production and decomposition rates in the absence of soil animals. However, increased fungal biomass also stimulated consumption rates by soil invertebrates, restoring microbial process rates to levels observed under ambient conditions. Our results support the contemporary theory that top-down control in soil food webs is apparent only in the absence of bottom-up limitation. As such, when global change factors alleviate the bottom-up limitations on microbial activity, top-down control becomes an increasingly important regulatory force with the capacity to dampen the strength of positive carbon cycle-climate feedbacks.
- MeSH
- analýza rozptylu MeSH
- dusík metabolismus MeSH
- houby fyziologie MeSH
- Isopoda fyziologie MeSH
- klimatické změny * MeSH
- potravní řetězec * MeSH
- půdní mikrobiologie * MeSH
- teoretické modely * MeSH
- zpětná vazba * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Geografické názvy
- Massachusetts MeSH
