排序方式: 共有9条查询结果,搜索用时 250 毫秒
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Read TD Peterson SN Tourasse N Baillie LW Paulsen IT Nelson KE Tettelin H Fouts DE Eisen JA Gill SR Holtzapple EK Okstad OA Helgason E Rilstone J Wu M Kolonay JF Beanan MJ Dodson RJ Brinkac LM Gwinn M DeBoy RT Madpu R Daugherty SC Durkin AS Haft DH Nelson WC Peterson JD Pop M Khouri HM Radune D Benton JL Mahamoud Y Jiang L Hance IR Weidman JF Berry KJ Plaut RD Wolf AM Watkins KL Nierman WC Hazen A Cline R Redmond C Thwaite JE White O Salzberg SL Thomason B Friedlander AM Koehler TM Hanna PC 《Nature》2003,423(6935):81-86
Bacillus anthracis is an endospore-forming bacterium that causes inhalational anthrax. Key virulence genes are found on plasmids (extra-chromosomal, circular, double-stranded DNA molecules) pXO1 (ref. 2) and pXO2 (ref. 3). To identify additional genes that might contribute to virulence, we analysed the complete sequence of the chromosome of B. anthracis Ames (about 5.23 megabases). We found several chromosomally encoded proteins that may contribute to pathogenicity--including haemolysins, phospholipases and iron acquisition functions--and identified numerous surface proteins that might be important targets for vaccines and drugs. Almost all these putative chromosomal virulence and surface proteins have homologues in Bacillus cereus, highlighting the similarity of B. anthracis to near-neighbours that are not associated with anthrax. By performing a comparative genome hybridization of 19 B. cereus and Bacillus thuringiensis strains against a B. anthracis DNA microarray, we confirmed the general similarity of chromosomal genes among this group of close relatives. However, we found that the gene sequences of pXO1 and pXO2 were more variable between strains, suggesting plasmid mobility in the group. The complete sequence of B. anthracis is a step towards a better understanding of anthrax pathogenesis. 相似文献
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DNA sequence of both chromosomes of the cholera pathogen Vibrio cholerae 总被引:23,自引:0,他引:23
Heidelberg JF Eisen JA Nelson WC Clayton RA Gwinn ML Dodson RJ Haft DH Hickey EK Peterson JD Umayam L Gill SR Nelson KE Read TD Tettelin H Richardson D Ermolaeva MD Vamathevan J Bass S Qin H Dragoi I Sellers P McDonald L Utterback T Fleishmann RD Nierman WC White O Salzberg SL Smith HO Colwell RR Mekalanos JJ Venter JC Fraser CM 《Nature》2000,406(6795):477-483
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研究超声波经过两个烧结样品的行为.两个烧结样品为有序的面心立方结构,它们的结构几乎相同.研究表明:在两个有序的准均匀的介质中分别有一个禁带区域.就禁带区域而言,在两个样品中产生禁带的区域非常接近.同时在禁带出现的区域群速度为负值.我们的结果表明群速度的负值的确存在于有序介质中的禁带区域内. 相似文献
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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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Ioannidis JP Gwinn M Little J Higgins JP Bernstein JL Boffetta P Bondy M Bray MS Brenchley PE Buffler PA Casas JP Chokkalingam A Danesh J Smith GD Dolan S Duncan R Gruis NA Hartge P Hashibe M Hunter DJ Jarvelin MR Malmer B Maraganore DM Newton-Bishop JA O'Brien TR Petersen G Riboli E Salanti G Seminara D Smeeth L Taioli E Timpson N Uitterlinden AG Vineis P Wareham N Winn DM Zimmern R Khoury MJ;Human Genome Epidemiology Network the Network of Investigator Networks 《Nature genetics》2006,38(1):3-5
Networks of investigators have begun sharing best practices, tools and methods for analysis of associations between genetic variation and common diseases. A Network of Investigator Networks has been set up to drive the process, sponsored by the Human Genome Epidemiology Network. A workshop is planned to develop consensus guidelines for reporting results of genetic association studies. Published literature databases will be integrated, and unpublished data, including 'negative' studies, will be captured by online journals and through investigator networks. Systematic reviews will be expanded to include more meta-analyses of individual-level data and prospective meta-analyses. Field synopses will offer regularly updated overviews. 相似文献
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The Virginia opossum ( Didelphis virginiana ) is the only marsupial native to the United States. In recent times, D. virginiana has expanded its range through natural movements and anthropogenic introductions. Didelphis virginiana has been present in southern Arizona owing to range expansion by the Mexican subspecies ( D. v. californica ) and anthropogenic introductions of the eastern subspecies ( D. v. virginiana ). Here, we document the recent collection of an opossum in central Arizona. We also discuss how it possibly moved there and report on its stomach contents at the time of collection. El tlacuache norteño ( Didelphis virginiana ) es el único marsupial nativo de Estados Unidos. En tiempos recientes, D. virginiana ha expandido su área de distribución tanto por movimientos naturales como por introducciones antropogénicas. Didelphis virginiana se ha encontrado en el sur de Arizona debido a la expansión de la subespecie mexicana ( D. v. californica ) y a introducciones antropogénicas de la subespecie oriental ( D. v. virginiana ). Aquí documentamos la colecta reciente de un tlacuache en el centro de Arizona. También discutimos cómo podría haber llegado hasta allí e informamos sobre los contenidos de su estómago al tiempo de la colecta. 相似文献
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Baur JA Pearson KJ Price NL Jamieson HA Lerin C Kalra A Prabhu VV Allard JS Lopez-Lluch G Lewis K Pistell PJ Poosala S Becker KG Boss O Gwinn D Wang M Ramaswamy S Fishbein KW Spencer RG Lakatta EG Le Couteur D Shaw RJ Navas P Puigserver P Ingram DK de Cabo R Sinclair DA 《Nature》2006,444(7117):337-342
Resveratrol (3,5,4'-trihydroxystilbene) extends the lifespan of diverse species including Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster. In these organisms, lifespan extension is dependent on Sir2, a conserved deacetylase proposed to underlie the beneficial effects of caloric restriction. Here we show that resveratrol shifts the physiology of middle-aged mice on a high-calorie diet towards that of mice on a standard diet and significantly increases their survival. Resveratrol produces changes associated with longer lifespan, including increased insulin sensitivity, reduced insulin-like growth factor-1 (IGF-I) levels, increased AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC-1alpha) activity, increased mitochondrial number, and improved motor function. Parametric analysis of gene set enrichment revealed that resveratrol opposed the effects of the high-calorie diet in 144 out of 153 significantly altered pathways. These data show that improving general health in mammals using small molecules is an attainable goal, and point to new approaches for treating obesity-related disorders and diseases of ageing. 相似文献
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世界的生物多样性很大程度上受到传统农业耕作方式的保护。这些生态上复杂的农业系统与作物遗传多样性中心相联系,有传统的栽培品种或“地方品种”,作为世界作物遗传资源的重要组成,还有野生的植物和动物种群,作为生物资源服务于人类。 相似文献
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