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Stephen J. O'Brien

Bio: Stephen J. O'Brien is an academic researcher from Saint Petersburg State University of Information Technologies, Mechanics and Optics. The author has contributed to research in topics: Population & Gene. The author has an hindex of 153, co-authored 1062 publications receiving 93025 citations. Previous affiliations of Stephen J. O'Brien include University College Cork & QIMR Berghofer Medical Research Institute.


Papers
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Journal ArticleDOI
01 Apr 1999-Genomics
TL;DR: A genetic linkage map of microsatellite loci in the feline genome has been constructed including 246 autosomal and 7 X-linked loci, which provides a valuable resource for mapping phenotypic variation in the species and relating it to gene maps of other mammals, including human.

445 citations

Journal ArticleDOI
27 Jul 2007-Science
TL;DR: A genetic assessment of 979 domestic cats and their wild progenitors revealed that cats were domesticated in the Near East, probably coincident with agricultural village development in the Fertile Crescent.
Abstract: The world's domestic cats carry patterns of sequence variation in their genome that reflect a history of domestication and breed development. A genetic assessment of 979 domestic cats and their wild progenitors-Felis silvestris silvestris (European wildcat), F. s. lybica (Near Eastern wildcat), F. s. ornata (central Asian wildcat), F. s. cafra (southern African wildcat), and F. s. bieti (Chinese desert cat)-indicated that each wild group represents a distinctive subspecies of Felis silvestris. Further analysis revealed that cats were domesticated in the Near East, probably coincident with agricultural village development in the Fertile Crescent. Domestic cats derive from at least five founders from across this region, whose descendants were transported across the world by human assistance.

430 citations

Journal ArticleDOI
TL;DR: A list of 321 reference anchor loci suitable for comparative gene mapping in mammals and other vertebrate classes is proposed and it is believed that the map may provide the basis for a unified approach to comparative analysis of mammalian species genomes.
Abstract: Recent advances in gene mapping technologies have led to increased emphasis in developing representative genetic maps for several species, particularly domestic plants and animals. These maps are being compiled with two distinct goals: to provide a resource for genetic analysis, and to help dissect the evolution of genome organization by comparing linkage relationships of homologous genes. We propose here a list of 321 reference anchor loci suitable for comparative gene mapping in mammals and other vertebrate classes. We selected cloned mouse and human functional genes spaced an average of 5–10 centiMorgans throughout their respective genomes. We also attempted to include loci that are evolutionary conserved and represented in comparative gene maps in other mammalian orders, particularly cattle and the domestic cat. We believe that the map may provide the basis for a unified approach to comparative analysis of mammalian species genomes.

429 citations

Journal ArticleDOI
08 Mar 1991-Science
TL;DR: The interpretive difficulties posed by molecular results for four endangered groups are summarized and three opinions from the Solicitor's Office of the Department of the Interior have ruled with the force of precedent that hybrids between endangered species, subspecies, or populations cannot be protected.
Abstract: of the Act by well-intentioned government officials. The listing of certain species as endangered has encouraged an increase in investigation of these taxa, notably in molecular genetics and field ecology (1). In some cases the molecular genetic results contradicted previous ideas about species integrity or taxonomic distinctions that were based on phenotypic (morphological) descriptions. Unfortunately these traditional taxonomic designations have been and continue to be the bases for management and eligibility for protection. This is a significant problem because the Endangered Species Act not only protects listed taxa from hunting, habitat exploitation, and other perils associated with human coexistence, but also provides significant financial resources for the effort to protect these species and to stabilize their populations. To illustrate the problem we summarize the interpretive difficulties posed by molecular results for four endangered groups. The Florida panther. This is a small population of mountain lion (also called cougar or puma) that descended from the Felis concolor coryi subspecies that ranged throughout the southern United States in the 19th century (2). The few remaining panthers (c50) living in southern Florida show significant physiological and reproductive impairments that are likely the consequence of inbreeding depression. A recent allozyme and mitochondrial DNA (mtDNA) analysis of the population revealed that two very distinct genetic stocks were living in Florida (2), one that resembled other North American pumas and another that was more closely related to a puma subspecies that had evolved in South America. Apparently seven animals from a captive stock (that later turned out to be a mixture of authentic F. concolor coryi and South American founders) were released into the Everglades between 1957 and 1967 and promptly forgotten. Today the founder ecosystem contains a mixture of two subspecies. The genetic advantages of introducing some additional genetic material into a population suffering from inbreeding would have been comforting except for one detail. Three opinions from the Solicitor's Office of the Department of the Interior (which is the counsel of the U.S. Fish and Wildlife Service) have ruled with the force of precedent that hybrids between endangered species, subspecies, or populations cannot be protected. Their opinions, referred to here as the Hybrid Policy, concluded that protection of hybrids would not serve to recover listed species and would likely jeopardize S.J. O'Brien is chief of the Laboratory of Viral Carcinogenesis, National Cancer

420 citations

Journal Article
TL;DR: Three continuous lines of mammary tumor cells have been established from malignant effusions of two women with breast cancer, and two of the cultures, although derived from the same patient, have stable differences in their karyotypes.
Abstract: Three continuous lines of mammary tumor cells (ZR-75-1, ZR-75-27, and ZR-75-30) have been established from malignant effusions of two women with breast cancer. Differentiated properties expressed by each cell line include: (a) epithelial morphology (by light and electron microscopy) resembling that of the parental tumors; (b) presence of receptors for estrogen and other steroid hormones; and (c) growth responsiveness to estrogen and/or progesterone. All three cell lines possess human karyotypes that differ from one another in modal chromosome number as well as in characteristic marker chromosomes. Two of the cultures (ZR-75-27 and ZR-75-30), although derived from the same patient, have stable differences in their karyotypes.

409 citations


Cited by
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Journal ArticleDOI
Eric S. Lander1, Lauren Linton1, Bruce W. Birren1, Chad Nusbaum1  +245 moreInstitutions (29)
15 Feb 2001-Nature
TL;DR: The results of an international collaboration to produce and make freely available a draft sequence of the human genome are reported and an initial analysis is presented, describing some of the insights that can be gleaned from the sequence.
Abstract: The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

22,269 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal Article
Fumio Tajima1
30 Oct 1989-Genomics
TL;DR: It is suggested that the natural selection against large insertion/deletion is so weak that a large amount of variation is maintained in a population.

11,521 citations

Journal ArticleDOI
Paul Burton1, David Clayton2, Lon R. Cardon, Nicholas John Craddock3  +192 moreInstitutions (4)
07 Jun 2007-Nature
TL;DR: This study has demonstrated that careful use of a shared control group represents a safe and effective approach to GWA analyses of multiple disease phenotypes; generated a genome-wide genotype database for future studies of common diseases in the British population; and shown that, provided individuals with non-European ancestry are excluded, the extent of population stratification in theBritish population is generally modest.
Abstract: There is increasing evidence that genome-wide association ( GWA) studies represent a powerful approach to the identification of genes involved in common human diseases. We describe a joint GWA study ( using the Affymetrix GeneChip 500K Mapping Array Set) undertaken in the British population, which has examined similar to 2,000 individuals for each of 7 major diseases and a shared set of similar to 3,000 controls. Case-control comparisons identified 24 independent association signals at P < 5 X 10(-7): 1 in bipolar disorder, 1 in coronary artery disease, 9 in Crohn's disease, 3 in rheumatoid arthritis, 7 in type 1 diabetes and 3 in type 2 diabetes. On the basis of prior findings and replication studies thus-far completed, almost all of these signals reflect genuine susceptibility effects. We observed association at many previously identified loci, and found compelling evidence that some loci confer risk for more than one of the diseases studied. Across all diseases, we identified a large number of further signals ( including 58 loci with single-point P values between 10(-5) and 5 X 10(-7)) likely to yield additional susceptibility loci. The importance of appropriately large samples was confirmed by the modest effect sizes observed at most loci identified. This study thus represents a thorough validation of the GWA approach. It has also demonstrated that careful use of a shared control group represents a safe and effective approach to GWA analyses of multiple disease phenotypes; has generated a genome-wide genotype database for future studies of common diseases in the British population; and shown that, provided individuals with non-European ancestry are excluded, the extent of population stratification in the British population is generally modest. Our findings offer new avenues for exploring the pathophysiology of these important disorders. We anticipate that our data, results and software, which will be widely available to other investigators, will provide a powerful resource for human genetics research.

9,244 citations