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111.
Rogers AD Tyler PA Connelly DP Copley JT James R Larter RD Linse K Mills RA Garabato AN Pancost RD Pearce DA Polunin NV German CR Shank T Boersch-Supan PH Alker BJ Aquilina A Bennett SA Clarke A Dinley RJ Graham AG Green DR Hawkes JA Hepburn L Hilario A Huvenne VA Marsh L Ramirez-Llodra E Reid WD Roterman CN Sweeting CJ Thatje S Zwirglmaier K 《PLoS biology》2012,10(1):e1001234
Since the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised. 相似文献
112.
Sheth B Nowak RL Anderson R Kwong WY Papenbrock T Fleming TP 《Experimental cell research》2008,314(18):3356-3368
Apicolateral tight junctions (TJs) between epithelial cells are multiprotein complexes regulating membrane polarity and paracellular transport and also contribute to signalling pathways affecting cell proliferation and gene expression. ZO-2 and other ZO family members form a sub-membranous scaffold for binding TJ constituents. We investigated ZO-2 contribution to TJ biogenesis and function during trophectoderm epithelium differentiation in mouse preimplantation embryos. Our data indicate that ZO-2 is expressed from maternal and embryonic genomes with maternal ZO-2 protein associated with nuclei in zygotes and particularly early cleavage stages. Embryonic ZO-2 assembled at outer blastomere apicolateral junctional sites from the late 16-cell stage. Junctional ZO-2 first co-localised with E-cadherin in a transient complex comprising adherens junction and TJ constituents before segregating to TJs after their separation from the blastocyst stage (32-cell onwards). ZO-2 siRNA microinjection into zygotes or 2-cell embryos resulted in specific knockdown of ZO-2 mRNA and protein within blastocysts. Embryos lacking ZO-2 protein at trophectoderm TJs exhibited delayed blastocoel cavity formation but underwent normal cell proliferation and outgrowth morphogenesis. Quantitative analysis of trophectoderm TJs in ZO-2-deficient embryos revealed increased assembly of ZO-1 but not occludin, indicating ZO protein redundancy as a compensatory mechanism contributing to the mild phenotype observed. In contrast, ZO-1 knockdown, or combined ZO-1 and ZO-2 knockdown, generated a more severe inhibition of blastocoel formation indicating distinct roles for ZO proteins in blastocyst morphogenesis. 相似文献
113.
Screening of 445 animal faecal samples in irrigation catchments in Western Australia (WA) was conducted to identify the prevalence of Cryptosporidium and Giardia species. Of the samples positive for Giardia duodenalis, 30.7% (12/36) were the zoonotic Assemblage A, while approximately 13% (4/30) of Cryptosporidium positives were zoonotic. This is the first finding of Giardia Assemblage A in native marsupials and birds and indicates that marsupials and possibly birds may potentially be a reservoir of zoonotic Giardia. 相似文献
114.
Rachael Winfree 《Animal Conservation》2004,7(4):445-453
115.
Optimal foraging theory explains diet restriction as an adaptation to best utilize an array of foods differing in quality, the poorest items not worth the lost opportunity of finding better ones. Although optimal foraging has traditionally been applied to animal behavior, the model is easily applied to viral host range, which is genetically determined. The usual perspective for bacteriophages (bacterial viruses) is that expanding host range is always advantageous if fitness on former hosts is not compromised. However, foraging theory identifies conditions favoring avoidance of poor hosts even if larger host ranges have no intrinsic costs. Bacteriophage T7 rapidly evolved to discriminate among different Escherichia coli strains when one host strain was engineered to kill infecting phages but the other remained productive. After modifying bacteria to yield more subtle fitness effects on T7, we tested qualitative predictions of optimal foraging theory by competing broad and narrow host range phages against each other. Consistent with the foraging model, diet restriction was favored when good hosts were common or there was a large difference in host quality. Contrary to the model, the direction of selection was affected by the density of poor hosts because being able to discriminate was costly. 相似文献
116.
Tertius A. Hough Patrick M. Nolan Vicky Tsipouri Ayo A. Toye Ian C. Gray Michelle Goldsworthy Lee Moir Roger D. Cox Sian Clements Peter H. Glenister John Wood Rachael L. Selley Mark A. Strivens Lucie Vizor Stefan L. McCormack Josephine Peters Elizabeth M. Fisher Nigel Spurr Sohaila Rastan Joanne E. Martin Steve D.M. Brown A. Jacqueline Hunter 《Mammalian genome》2002,13(10):595-602
We used ENU mutagenesis in the mouse for the rapid generation of novel mutant phenotypes for both gene function studies and use as new animal models of human disease (Nolan et al. 2000b). One focus of the program was the development of a blood biochemistry screen. At 8-12 weeks of age, approximately 300 ml of blood was collected from F1 offspring of ENU mutagenized male mice. This yielded approximately 125 ml of plasma, used to perform a profile of 17 standard biochemical tests on an Olympus analyzer. Cohorts of F1 mice were also aged and then retested to detect late onset phenotypes. In total, 1,961 F1s were screened. Outliers were identified by running means and standard deviations. Of 70 mice showing consistent abnormalities in plasma biochemistry, 29 were entered into inheritance testing. Of these, 9 phenotypes were confirmed as inherited, 10 found not to be inherited, and 10 are still being tested. Inherited mutant phenotypes include abnormal lipid profiles (low total and HDL cholesterol, high triglycerides); abnormalities in bone and liver metabolism (low ALP, high ALP, high ALT, and AST); abnormal plasma electrolyte levels (high sodium and chloride); as well as phenotypes of interest for the study of diabetes (high glucose). The gene loci bearing the mutations are currently being mapped and further characterized. Our results have validated our biochemical screen, which is applicable to other mutagenesis projects, and we have produced a new set of mutants with defined metabolic phenotypes. 相似文献
117.
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119.
David A. Sandham Claire Adcock Kamlesh Bala Lucy Barker Zarin Brown Gerald Dubois David Budd Brian Cox Robin A. Fairhurst Markus Furegati Catherine Leblanc Jodie Manini Rachael Profit John Reilly Rowan Stringer Alfred Schmidt Katharine L. Turner Simon J. Watson Jennifer Willis Gareth Williams Caroline Wilson 《Bioorganic & medicinal chemistry letters》2009,19(16):4794-4798
High throughput screening identified a 7-azaindole-3-acetic acid scaffold as a novel CRTh2 receptor antagonist chemotype, which could be optimised to furnish a highly selective compound with good functional potency for inhibition of human eosinophil shape change in whole blood and oral bioavailability in the rat. 相似文献
120.