An animal's fitness strongly depends on successful feeding, avoidance of predators and reproduction. All of these behaviours commonly involve chemosensation. As a consequence, when species' ecological niches and life histories differ, their chemosensory abilities need to be adapted accordingly. The intertidal insect Clunio marinus (Diptera: Chironomidae) has tuned its olfactory system to two highly divergent niches. The long-lived larvae forage in a marine environment. During the few hours of terrestrial adult life, males have to find the female pupae floating on the water surface, free the cryptic females from their pupal skin, copulate and carry the females to the oviposition sites. In order to explore the possibility for divergent olfactory adaptations within the same species, we investigated the chemosensory system of C. marinus larvae, adult males and adult females at the morphological and molecular level. The larvae have a well-developed olfactory system, but olfactory gene expression only partially overlaps with that of adults, likely reflecting their marine vs. terrestrial lifestyles. The olfactory system of the short-lived adults is simple, displaying no glomeruli in the antennal lobes. There is strong sexual dimorphism, the female olfactory system being particularly reduced in terms of number of antennal annuli and sensilla, olfactory brain centre size and gene expression. We found hints for a pheromone detection system in males, including large trichoid sensilla and expression of specific olfactory receptors and odorant binding proteins. Taken together, this makes C. marinus an excellent model to study within-species evolution and adaptation of chemosensory systems.
- MeSH
- biologická adaptace fyziologie MeSH
- bulbus olfactorius metabolismus fyziologie MeSH
- Chironomidae metabolismus fyziologie MeSH
- čich fyziologie MeSH
- čichové buňky metabolismus MeSH
- hmyz metabolismus fyziologie MeSH
- hmyzí proteiny metabolismus MeSH
- kladení vajíček fyziologie MeSH
- kukla metabolismus fyziologie MeSH
- larva metabolismus MeSH
- pohlavní dimorfismus * MeSH
- receptory pachové metabolismus MeSH
- sensilla metabolismus fyziologie MeSH
- vodní organismy metabolismus fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- kmenové buňky MeSH
- mořská biologie dějiny MeSH
- rozmnožování MeSH
- spermie MeSH
- vodní organismy fyziologie MeSH
- zvířata MeSH
- Check Tag
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- biografie MeSH
- časopisecké články MeSH
- historické články MeSH
Environmental pollution by pharmaceutically active compounds, used in quantities similar to those of pesticides and other organic micropollutants, is increasingly recognized as a major threat to the aquatic environment. These compounds are only partly removed from wastewaters and, despite their low concentrations, directly and indirectly affect behaviour of freshwater organisms in natural habitats. The aim of this study was to behaviourally assess the effects of an opioid painkiller (tramadol) and antidepressant drug (citalopram) on behaviour patterns of a clonal model species, marbled crayfish. Animals exposed to environmentally relevant concentrations of both tested compounds (∼1 μg l-1) exhibited significantly lower velocity and shorter distance moved than controls. Crayfish exposed to tramadol spent more time in shelters. Results were obtained by a simple and rapid method recommended as suitable for assessment of behaviour in aquatic organisms exposed to single pollutants and combinations.
- MeSH
- bezobratlí účinky léků fyziologie MeSH
- chemické látky znečišťující vodu toxicita MeSH
- chování zvířat účinky léků MeSH
- citalopram toxicita MeSH
- pohyb účinky léků MeSH
- severní raci účinky léků fyziologie MeSH
- tramadol toxicita MeSH
- vodní organismy účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Diatoms greatly contribute to carbon fixation and thus strongly influence the global biogeochemical balance. Capable of chromatic acclimation (CA) to unfavourable light conditions, diatoms often dominate benthic ecosystems in addition to their planktonic lifestyle. Although CA has been studied at the molecular level, our understanding of this phenomenon remains incomplete. Here we provide new data to better explain the acclimation-associated changes under red-enhanced ambient light (RL) in diatom Phaeodactylum tricornutum, known to express a red-shifted antenna complex (F710). The complex was found to be an oligomer of a single polypeptide, Lhcf15. The steady-state spectroscopic properties of the oligomer were also studied. The oligomeric assembly of the Lhcf15 subunits is required for the complex to exhibit a red-shifted absorption. The presence of the red antenna in RL culture coincides with the development of a rounded phenotype of the diatom cell. A model summarizing the modulation of the photosynthetic apparatus during the acclimation response to light of different spectral quality is proposed. Our study suggests that toggling between alternative organizations of photosynthetic apparatus and distinct cell morphologies underlies the remarkable acclimation capacity of diatoms.
- MeSH
- fenotyp * MeSH
- fyziologická adaptace MeSH
- multimerizace proteinu MeSH
- rozsivky fyziologie účinky záření MeSH
- spektrální analýza MeSH
- světlosběrné proteinové komplexy metabolismus MeSH
- vodní organismy fyziologie účinky záření MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Marine organisms adapt to complex temporal environments that include daily, tidal, semi-lunar, lunar and seasonal cycles. However, our understanding of marine biological rhythms and their underlying molecular basis is mainly confined to a few model organisms in rather simplistic laboratory settings. Here, we use new empirical data and recent examples of marine biorhythms to highlight how field ecologists and laboratory chronobiologists can complement each other's efforts. First, with continuous tracking of intertidal shorebirds in the field, we reveal individual differences in tidal and circadian foraging rhythms. Second, we demonstrate that shorebird species that spend 8-10 months in tidal environments rarely maintain such tidal or circadian rhythms during breeding, likely because of other, more pertinent, temporally structured, local ecological pressures such as predation or social environment. Finally, we use examples of initial findings from invertebrates (arthropods and polychaete worms) that are being developed as model species to study the molecular bases of lunar-related rhythms. These examples indicate that canonical circadian clock genes (i.e. the homologous clock genes identified in many higher organisms) may not be involved in lunar/tidal phenotypes. Together, our results and the examples we describe emphasize that linking field and laboratory studies is likely to generate a better ecological appreciation of lunar-related rhythms in the wild.This article is part of the themed issue 'Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals'.
- MeSH
- Charadriiformes fyziologie MeSH
- cirkadiánní hodiny * MeSH
- cirkadiánní rytmus * MeSH
- cizopasní červi fyziologie MeSH
- členovci fyziologie MeSH
- vodní organismy fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- biodegradace MeSH
- čištění vody metody MeSH
- environmentální zdraví statistika a číselné údaje MeSH
- látky znečišťující vodu analýza toxicita MeSH
- mikrobiologie vody MeSH
- testy toxicity metody MeSH
- vodní organismy účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- úvodní články MeSH
- úvodníky MeSH
The world's oceans represent by far the largest biome, with great importance for the global ecosystem [1-4]. The vast majority of ocean biomass and biodiversity is composed of microscopic plankton. Recent results from the Tara Oceans metabarcoding study revealed that a significant part of the plankton in the upper sunlit layer of the ocean is represented by an understudied group of heterotrophic excavate flagellates called diplonemids [5, 6]. We have analyzed the diversity and distribution patterns of diplonemid populations on the extended set of Tara Oceans V9 18S rDNA metabarcodes amplified from 850 size- fractionated plankton communities sampled across 123 globally distributed locations, for the first time also including samples from the mesopelagic zone, which spans the depth from about 200 to 1,000 meters. Diplonemids separate into four major clades, with the vast majority falling into the deep-sea pelagic diplonemid clade. Remarkably, diversity of this clade inferred from metabarcoding data surpasses even that of dinoflagellates, metazoans, and rhizarians, qualifying diplonemids as possibly the most diverse group of marine planktonic eukaryotes. Diplonemids display strong vertical separation between the photic and mesopelagic layers, with the majority of their relative abundance and diversity occurring in deeper waters. Globally, diplonemids display no apparent biogeographic structuring, with a few hyperabundant cosmopolitan operational taxonomic units (OTUs) dominating their communities. Our results suggest that the planktonic diplonemids are among the key heterotrophic players in the largest ecosystem of our biosphere, yet their roles in this ecosystem remain unknown.
- MeSH
- biodiverzita * MeSH
- ekosystém * MeSH
- Euglenozoa klasifikace genetika MeSH
- oceány a moře MeSH
- plankton klasifikace genetika MeSH
- RNA protozoální genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza RNA MeSH
- taxonomické DNA čárové kódování MeSH
- vodní organismy fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- oceány a moře MeSH
Lukeš et al. introduce an enigmatic group of unicellular eukaryotes called the diplonemids, which according to recent surveys may be widespread in marine ecosystems.
- MeSH
- biodiverzita * MeSH
- Euglenozoa klasifikace genetika fyziologie MeSH
- vodní organismy klasifikace genetika fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
Recognition of the environmental role of photoheterotrophic bacteria has been one of the main themes of aquatic microbiology over the last 15 years. Aside from cyanobacteria and proteorhodopsin-containing bacteria, aerobic anoxygenic phototrophic (AAP) bacteria are the third most numerous group of phototrophic prokaryotes in the ocean. This functional group represents a diverse assembly of species which taxonomically belong to various subgroups of Alpha-, Beta- and Gammaproteobacteria. AAP bacteria are facultative photoheterotrophs which use bacteriochlorophyll-containing reaction centers to harvest light energy. The light-derived energy increases their bacterial growth efficiency, which provides a competitive advantage over heterotrophic species. Thanks to their enzymatic machinery AAP bacteria are active, rapidly growing organisms which contribute significantly to the recycling of organic matter. This chapter summarizes the current knowledge of the ecology of AAP bacteria in aquatic environments, implying their specific role in the microbial loop.
- MeSH
- aerobní bakterie fyziologie MeSH
- biodiverzita MeSH
- ekologie MeSH
- fototrofní procesy fyziologie MeSH
- mikrobiologie vody * MeSH
- oceány a moře MeSH
- potravní řetězec MeSH
- vodní organismy fyziologie MeSH
- životní prostředí * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Geografické názvy
- oceány a moře MeSH
