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51.
Martina Höckner Reinhard Dallinger Stephen R. Stürzenbaum 《Journal of biological inorganic chemistry》2011,16(7):1057-1065
Metallobiologists have, at large, neglected soil dwelling invertebrates; exceptions are the nematode (Caenorhabditis elegans) and snails (Helix pomatia and Cantareus aspersus). This review aims to compare and contrast the molecular, protein and cellular mechanisms of the multifunctional nematode
and snail metallothioneins (MTs). The C. elegans genome contains two MT genes, mtl-1, which is constitutively expressed in the pharynx and likely to act as an essential and/or toxic metal sensor, and mtl-2, which plays a negligible role under normal physiological conditions but is strongly induced (as mtl-1) in intestinal cells upon metal exposure. It has been possible to follow the intricate phenotypic responses upon the knockdown/knockout
of single and multiple MT isoforms and we have started to decipher the multifunctional role of C. elegans MTs. The snails have contributed to our understanding regarding MT evolution and diversity, structure and metal-specific
functionality. The H. pomatia and C. aspersus genomes contain at least three MT isoform genes. CdMT is responsible for cadmium detoxification, CuMT is involved in copper
homeostasis and Cd/CuMT is a putative ancestral MT possibly only of minor importance in metal metabolism. Further investigations
of nematode, snail and other invertebrate MTs will allow the development of alternative biomarker approaches and lead to an
improved understanding of metallobiology, protein evolution and toxicogenomics. 相似文献
52.
A new halacarid species, Halacarellus fontinalis n. sp., from a spring in the Gesäuse National Park, Austria is described. The species is characterized by three pairs of large, equal-sized acetabula and slender claws and is expected to have evolved in the Tertiary from a Tethyan-Paratethyan Halacarellus species. CaspihalacarusViets, 1928, with a single species, C. hyrcanusViets, 1928, has large and external acetabula similar to those in H. fontinalis. Caspihalacarus is synonymized with Halacarellus. 相似文献
53.
Silke Krüger Casey S. Butler Reinhard Lakes-Harlan 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2011,197(2):181-192
Orthopterans are suitable model organisms for investigations of regeneration mechanisms in the auditory system. Regeneration
has been described in the auditory systems of locusts (Caelifera) and of crickets (Ensifera). In this study, we comparatively
investigate the neural regeneration in the auditory system in the bush cricket Mecopoda elongata. A crushing of the tympanal nerve in the foreleg of M. elongata results in a loss of auditory information transfer. Physiological recordings of the tympanal nerve suggest outgrowing fibers
5 days after crushing. An anatomical regeneration of the fibers within the central nervous system starts 10 days after crushing.
The neuronal projection reaches the target area at day 20. Threshold values to low frequency airborne sound remain high after
crushing, indicating a lower regeneration capability of this group of fibers. However, within the central target area the
low frequency areas are also innervated. Recordings of auditory interneurons show that the regenerating fibers form new functional
connections starting at day 20 after crushing. 相似文献
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Òscar Palacios Ayelen Pagani Sílvia Pérez-Rafael Margit Egg Martina Höckner Anita Brandstätter Mercè Capdevila Sílvia Atrian Reinhard Dallinger 《BMC biology》2011,9(1):4
Background
The degree of metal binding specificity in metalloproteins such as metallothioneins (MTs) can be crucial for their functional accuracy. Unlike most other animal species, pulmonate molluscs possess homometallic MT isoforms loaded with Cu+ or Cd2+. They have, so far, been obtained as native metal-MT complexes from snail tissues, where they are involved in the metabolism of the metal ion species bound to the respective isoform. However, it has not as yet been discerned if their specific metal occupation is the result of a rigid control of metal availability, or isoform expression programming in the hosting tissues or of structural differences of the respective peptides determining the coordinative options for the different metal ions. In this study, the Roman snail (Helix pomatia) Cu-loaded and Cd-loaded isoforms (HpCuMT and HpCdMT) were used as model molecules in order to elucidate the biochemical and evolutionary mechanisms permitting pulmonate MTs to achieve specificity for their cognate metal ion. 相似文献59.
Hotspots of biotic compositional change in lakes along vast latitudinal transects in northern Canada
milie Saulnier‐Talbot Dermot Antoniades Reinhard Pienitz 《Global Change Biology》2020,26(4):2270-2279
Ecotones mark zones of rapid change in ecological structure at various spatial scales. They are believed to be particularly susceptible to shifts caused by environmental transformation, making them key regions for studying the effects of global change. Here, we explored the variation in assemblage structure of aquatic primary producer and consumer communities across latitudinal transects in northeastern North America (Québec‐Labrador) to identify spatial patterns in biodiversity that indicated the location of transition zones across the landscape. We analyzed species richness and the cumulative rate of compositional change (expressed as beta‐diversity) of diatoms and chironomids to detect any abrupt shifts in the rate of spatial taxonomic turnover. We used principal coordinates analysis to estimate community turnover with latitude, then applied piecewise linear regression to assess the position of ecotones. Statistically significant changes in assemblage composition occurred at 52 and 55°N, corresponding to the transition between closed‐ and open‐crown forest, and to the southern onset of the forest tundra (i.e., the forest limit), respectively. The spatial distribution of ecotones was most strongly related to air temperature for chironomids and to vegetation‐ and soil‐related chemical attributes of lake water for diatoms, including dissolved organic carbon content and water color. Lakes at mid‐ to high‐latitudes currently face pressures from rapidly rising temperatures, accompanied by large increases in organic carbon inputs from their catchments, often leading to browning and its associated effects. The biota at the base of food webs in lakes located in transition zones are disproportionately affected by the cascading effects of these multi‐factorial changes, concurrent with pronounced terrestrial greening observed in these regions. Similar patterns of biotic shifts have been observed along alpine aquatic transects, indicating the potential for widespread restructuring of cold, high‐altitude and high‐latitude freshwater communities due to global change. 相似文献