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Evidence for lateral gene transfer between Archaea and bacteria from genome sequence of Thermotoga maritima. 总被引:27,自引:0,他引:27
K E Nelson R A Clayton S R Gill M L Gwinn R J Dodson D H Haft E K Hickey J D Peterson W C Nelson K A Ketchum L McDonald T R Utterback J A Malek K D Linher M M Garrett A M Stewart M D Cotton M S Pratt C A Phillips D Richardson J Heidelberg G G Sutton R D Fleischmann J A Eisen O White S L Salzberg H O Smith J C Venter C M Fraser 《Nature》1999,399(6734):323-329
The 1,860,725-base-pair genome of Thermotoga maritima MSB8 contains 1,877 predicted coding regions, 1,014 (54%) of which have functional assignments and 863 (46%) of which are of unknown function. Genome analysis reveals numerous pathways involved in degradation of sugars and plant polysaccharides, and 108 genes that have orthologues only in the genomes of other thermophilic Eubacteria and Archaea. Of the Eubacteria sequenced to date, T. maritima has the highest percentage (24%) of genes that are most similar to archaeal genes. Eighty-one archaeal-like genes are clustered in 15 regions of the T. maritima genome that range in size from 4 to 20 kilobases. Conservation of gene order between T. maritima and Archaea in many of the clustered regions suggests that lateral gene transfer may have occurred between thermophilic Eubacteria and Archaea. 相似文献
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Selected mouse lines, alcohol and behavior 总被引:3,自引:0,他引:3
The technique of selective breeding has been employed to develop a number of mouse lines differing in genetic sensitivity to specific effects of ethanol. Genetic animal models for sensitivity to the hypnotic, thermoregulatory, excitatory, and dependence-producing effects of alcohol have been developed. These genetic animal models have been utilized in numerous studies to assess the bases for those genetic differences, and to determine the specific neurochemical and neurophysiological bases for ethanol's actions. Work with these lines has challenged some long-held beliefs about ethanol's mechanisms of action. For example, lines genetically sensitive to one effect of ethanol are not necessarily sensitive to others, which demonstrates that no single set of genes modulates all ethanol effects. LS mice, selected for sensitivity to ethanol anesthesia, are not similarly sensitive to all anesthetic drugs, which demonstrates that all such drugs cannot have a common mechanism of action. On the other hand, WSP mice, genetically susceptible to the development of severe ethanol withdrawal, show a similar predisposition to diazepam and phenobarbital withdrawal, which suggests that there may be a common set of genes underlying drug dependencies. Studies with these models have also revealed important new directions for future mechanism-oriented research. Several studies implicate brain gamma-aminobutyric acid and dopamine systems as potentially important mediators of susceptibility to alcohol intoxication. The stability of the genetic animal models across laboratories and generations will continue to increase their power as analytic tools. 相似文献
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Summary In crude extracts, pea cotyledon acid ribonuclease is not inactivated by photodynamic treatment, but after 150-fold purification it is markedly inactivated when illuminated in the presence of rose bengal at pH 7.1. Data suggests that histidine photo-oxidation reduces catalytic activity. 相似文献
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S S Bhattacharya A F Wright J F Clayton W H Price C I Phillips C M McKeown M Jay A C Bird P L Pearson E M Southern 《Nature》1984,309(5965):253-255
Retinitis pigmentosa (RP) is a group of retinal degeneration characterized by progressive visual field loss, night blindness and pigmentary retinopathy. Its prevalence is in the region of 1-2 in 5,000 of the general population, making it one of the commoner causes of blindness in early and middle life. Although 36-48% of RP patients are isolated cases, the remainder show autosomal dominant, autosomal recessive or X-linked modes of inheritance. The X-linked variety ( XLRP ) is found in 14-22% of RP families in the UK. In the present study, X chromosome-specific recombinant DNA probes which can detect restriction fragment length polymorphisms have been used to localize the XLRP gene(s) to a subregion of the X chromosome using linkage analysis. One of the probes, L1.28, has been shown to be closely linked to XLRP in five kindreds, with 95% confidence limits of 0-15 centimorgans (maximum LOD score of 7.89 at a distance of 3 centimorgans). This suggests that the XLRP locus lies on the proximal part of the short arm of the X chromosome. This probe is potentially useful for carrier detection and early diagnosis in about 40% of cases, provided that genetic heterogeneity can be excluded by analysis of further families. 相似文献