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Nucleotide Polymorphism Markers (nucleotide + polymorphism_marker)
Kinds of Nucleotide Polymorphism Markers Selected AbstractsSix diagnostic single nucleotide polymorphism markers for detecting introgression between cutthroat and rainbow troutsMOLECULAR ECOLOGY RESOURCES, Issue 3 2009AMANDA J. FINGER Abstract Ten primer pairs were screened to develop single nucleotide polymorphism (SNP) TaqMan assays that will distinguish California golden trout and some rainbow trouts (Oncorhynchus mykiss sspp., O. m. aguabonita) from the Paiute and Lahontan cutthroat trouts (Oncorhynchus clarkii seleniris, O. c. henshawi). From these 10 primer pairs, one mitochondrial and five nuclear fixed SNP differences were discovered and developed into TaqMan assays. These six assays will be useful for characterizing and monitoring hybridization between these groups. Additional Oncorhynchus clarkii sspp. and Oncorhynchus mykiss sspp. were assayed to determine if these assays are useful in closely related species. [source] Characterization of single nucleotide polymorphism markers for the green sea turtle (Chelonia mydas)MOLECULAR ECOLOGY RESOURCES, Issue 3 2009SUZANNE E. RODEN Abstract We present data on 29 new single nucleotide polymorphism assays for the green sea turtle, Chelonia mydas. DNA extracts from 39 green turtles were used for two methods of single nucleotide polymorphism discovery. The first approach employed an amplified fragment length polymorphism technique. The second technique screened a microsatellite library. Allele-specific amplification assays were developed for high-throughput single nucleotide polymorphism genotyping and tested on two Pacific C. mydas nesting populations. Observed heterozygosities ranged from 0 to 0.95 for a Hawaiian population and from 0 to 0.85 for a Galapagos population. Each of the populations had one locus out of Hardy,Weinberg equilibrium, SSCM2b and SSCM5 for Hawaii and Galapagos, respectively. No loci showed significant genotypic linkage disequilibrium across an expanded set of four Pacific nesting populations. However, two loci, SSCM4 and SSCM10b showed linkage disequilibrium across three populations indicating possible association. [source] The evolution of tropical adaptation: comparing taurine and zebu cattleANIMAL GENETICS, Issue 5 2010E. K. F. Chan Summary Beef cattle breeds consist of three major genetic subdivisions. The taurine group is adapted to temperate environments, and the zebu and Sanga groups are both adapted to tropical environments. With the advent of genotyping and sequencing technologies in agriculture, genome-wide exploration of the genetic basis for the differences in tropical adaptation has only just become possible. In this study, approximately 9000 single nucleotide polymorphism markers were genotyped on 317 animals of a selection of taurine, zebu, and composite breeds to characterize any systematic differences between these groups. We identified 91 intra-breed-class markers; 78 were polymorphic only within the zebu animals, while 13 were polymorphic only in the taurine animals. There were no fixed differences (fixed for alternate alleles between the two breed types) between zebu and taurine animals. We found 14 regions with significantly different allele frequencies between zebu and taurine animals indicative of variable selection pressure or genetic drift. We also found 12 independent regions of differential extended haplotype homozygosity (EHH), indicative of recent selection or rapid fixation of the alternate allele within a short period of time in one of the two breed classes. A preliminary functional genomics analysis of these regions pointed towards signatures of tropical attributes including keratins, heat-shock proteins and heat resistance genes. We anticipate this investigation to be a stepping-stone for future studies to identify genomic regions specific to the two cattle groups, and to subsequently assist in the discrimination between temperate and tropically adapted cattle. [source] A SNP/microsatellite genetic linkage map of the Atlantic cod (Gadus morhua)ANIMAL GENETICS, Issue 6 2009T. Moen Summary A first genetic linkage map of the Atlantic cod (Gadus morhua) was produced, based on segregation data from 12 full-sib families of Norwegian origin. The map contained 174 single nucleotide polymorphism markers and 33 microsatellites, distributed on 25 linkage groups and had a length of 1225 cM. A significant difference in recombination rates between sexes was found, the average ratio of female:male recombination rates being 1.78 ± 1.62 (SD). [source] Characterization of 20 single nucleotide polymorphism markers in the Pacific oyster (Crassostrea gigas)ANIMAL GENETICS, Issue 6 2009J. Bai No abstract is available for this article. [source] Linkage disequilibrium in the North American Holstein populationANIMAL GENETICS, Issue 3 2009E.-S. Kim Summary Linkage disequilibrium was estimated using 7119 single nucleotide polymorphism markers across the genome and 200 animals from the North American Holstein cattle population. The analysis of maternally inherited haplotypes revealed strong linkage disequilibrium (r2 > 0.8) in genomic regions of ,50 kb or less. While linkage disequilibrium decays as a function of genomic distance, genomic regions within genes showed greater linkage disequilibrium and greater variation in linkage disequilibrium compared with intergenic regions. Identification of haplotype blocks could characterize the most common haplotypes. Although maximum haplotype block size was over 1 Mb, mean block size was 26,113 kb by various definitions, which was larger than that observed in humans (,10 kb). Effective population size of the dairy cattle population was estimated from linkage disequilibrium between single nucleotide polymorphism marker pairs in various haplotype ranges. Rapid reduction of effective population size of dairy cattle was inferred from linkage disequilibrium in recent generations. This result implies a loss of genetic diversity because of the high rate of inbreeding and high selection intensity in dairy cattle. The pattern observed in this study indicated linkage disequilibrium in the current dairy cattle population could be exploited to refine mapping resolution. Changes in effective population size during past generations imply a necessity of plans to maintain polymorphism in the Holstein population. [source] Putative common origin of two MLH1 mutations in Italian-Quebec hereditary non-polyposis colorectal cancer familiesCLINICAL GENETICS, Issue 2 2004I Thiffault Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common inherited cancer syndromes, accounting for 3,5% of all cases of colorectal cancer. In most HNPCC families, the disease is caused by a germline mutation in MLH1 or MSH2. In some populations, founder mutations appear to explain a substantial fraction of HNPCC. We report here the identification and preliminary characterization of two putative MLH1 founder mutations. The mutation MLH1c.1831delAT was shown to segregate in two Quebec families of Italian origin who fulfilled the Amsterdam criteria for HNPCC. Haplotype analysis using five intragenic microsatellite/single nucleotide polymorphism markers spanning MLH1 on chromosome 3 showed that these two unrelated families share an identical haplotype. In addition, two other Italian kindred whose affected members carry MLH1g.IVS6 + 3A>G also share a common haplotype, suggesting that, similarly, the latter mutation has a common origin. These mutations are the first putative founder MLH1 mutations to be identified in HNPCC kindred of Italian origin. [source] |