Search results for "Polymorphism"
showing 10 items of 1968 documents
A sensitive issue: Pyrosequencing as a valuable forensic SNP typing platform
2006
Analysing minute amounts of DNA is a routine challenge in forensics in part due to the poor sensitivity of an instrument and its inability to detect results from forensic samples. In this study, the sensitivity of the Pyrosequencing method is investigated using varying concentrations of DNA and five autosomal single nucleotide polymorphisms in singleplex on both available instrument models; the PSQ™ 96MA and PSQ™ HS 96A. A detailed comparison of the two models was completed while establishing a lower limit of detection on both instruments to give results supporting the use of Pyrosequencing as a valuable forensic SNP typing platform. © 2005 Elsevier B.V. All rights reserved.
DNA polymorphism of the human complement C8 beta gene: formal genetics and intragenic localization.
1989
The eighth component of human complement consists of three subunits of different molecular mass, which are coded for by three separate genetic loci. Polymorphisms have been described at the protein level for the alpha and beta subunits by means of sodium dodecyl sulfate gel electrophoresis and isoelectric focusing. Using a full-length human C8 beta cDNA probe, we have studied more than 100 individuals by Southern blot analysis to detect DNA polymorphisms. We have found two restriction fragment length polymorphisms (RFLPs) with the enzymes Taq I and Bam HI. The Taq I polymorphism is defined by two alleles, i.e., a single 4.9 kb fragment or two 2.8/2.1 kb fragments. The allele frequencies are…
Distortion of symmetrical introgression in a hybrid zone: evidence for locus-specific selection and uni-directional range expansion
2006
The fate of species integrity upon natural hybridization depends on the interaction between selection and dispersal. The relative significance of these processes may be studied in the initial phase of contact before selection and gene flow reach equilibrium. Here we study a hybrid zone of two salamander species, Lyciasalamandra antalyana and Lyciasalamandra billae, at the initial phase of hybridization. We quantify the degree and mode of introgression using nuclear and mtDNA markers. The hybrid zone can be characterized as an abrupt transition zone, the central hybrid zone being only c. 400 m, but introgressed genes were traced up to 3 km. Introgression was traced in both sexes but gene flo…
Cytokine Gene Polymorphisms and Breast Cancer Susceptibility
2006
Human breast cancer (BC) is characterized by a considerable clinical heterogeneity. Steroid hormone receptor expression and growth factor receptor expression have been considered suitable diagnostic and prognostic markers, whereas mutations of oncosuppressor and gatekeeper genes have been found associated with an increased risk for this malignancy. To evaluate the role that polymorphisms of genes involved in the regulation of inflammatory response might play in BC susceptibility, we investigated associations between cytokine functionally relevant polymorphisms in 84 BC patients compared to 110 age- and sex-matched controls. TNF-alpha (-308G/A), TGF-beta1 (+869C/T), IL-10 (-1117G/A; -854C/T;…
Effect of hairless gene polymorphism on the breeding values of milk production traits in Valle del Belice dairy sheep
2013
The aim of this work was to assess the association between the hairless genotypes and estimated breeding values (EBVs) for milk yield (MY), fat (FAT) and protein (PRT) content in Valle del Belice dairy sheep breed. A data set from 465 randomly chosen unrelated individuals was analyzed. EBV for MY, FAT and PRT contents were estimated by REML analysis of a single trait repeatability animal model. The genotype effect on EBV was assessed by ANOVA and by the Tukey–Kramer multiple comparison test. The PCR-SSCP test showed the presence of CC and CT genotypes in Valle del Belice individuals. Some differences in milk production traits between the genotypes were found. For MY, individuals with CT gen…
Amplified fragment length polymorphisms and sequence data in the phylogenetic analysis of polyploids: multiple origins of Veronica cymbalaria (Planta…
2007
Summary • The origin of polyploid Veronica cymbalaria (Plantaginaceae) was investigated using DNA sequence data and amplified fragment length polymorphism (AFLP) fingerprints to reveal the parentage of this taxon. The use of AFLP fingerprints in phylogenetic analysis is problematic and various methods have therefore been compared. • DNA sequence data (for the internal transcribed spacer (ITS) region and the plastid trnL-F region (trnL intron, 3’exon, and trnL-F spacer)) and polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis of the ITS region suggested a reliable hypothesis for the evolution of the V. cymbalaria complex. This hypothesis allowed evaluation …
A simple sequence repeat-based linkage map of barley.
2000
Abstract A total of 568 new simple sequence repeat (SSR)-based markers for barley have been developed from a combination of database sequences and small insert genomic libraries enriched for a range of short simple sequence repeats. Analysis of the SSRs on 16 barley cultivars revealed variable levels of informativeness but no obvious correlation was found with SSR repeat length, motif type, or map position. Of the 568 SSRs developed, 242 were genetically mapped, 216 with 37 previously published SSRs in a single doubled-haploid population derived from the F1 of an interspecific cross between the cultivar Lina and Hordeum spontaneum Canada Park and 26 SSRs in two other mapping populations. A …
Development and characterization of microsatellite markers in the Colorado potato beetle, Leptinotarsa decemlineata
2006
The characterization of 11 Leptinotarsa decemlineata microsatellite loci isolated using the fast isolation by AFLP of sequences containing repeats (FIASCO) protocol is reported. Three to 15 alleles per locus were detected in 54 beetles collected from four populations of L. decemlineata. The mean number of alleles was 7.4 ± 3.2 and the level of expected heterozygosity ranged from 0.451 to 0.798. The total exclusionary probabilities using these loci for the first and the second parent were 0.982 and 0.999, respectively. These are the first microsatellite loci characterized from the Colorado potato beetles that can be used for estimating genetic diversity, population structure and parentage an…
Chimerism and genetic diversity within the cultivar group of pinots
2002
Three clones of Vitis vinifera cv. pinot gris were analysed at 50 microsatellite loci to assess the presence of intra-varietal genetic variability. Two clones revealed a polymorphism expressed by the presence of three alleles at 5 loci instead of the two expected for a diploid species. By sequencing the three alleles amplified at two loci, we confirm that they correspond to different allelic states of the same locus but differ in their number of repeat units. Such tri-allelic profiles could reveal periclinal chimeras in which the two cell layers of the apical meristem are genetically different. For two clones, this periclinal chimeric state has been deduced from the comparison of the genoty…
A genome-wide view of Caenorhabditis elegans base-substitution mutation processes
2009
Knowledge of mutation processes is central to understanding virtually all evolutionary phenomena and the underlying nature of genetic disorders and cancers. However, the limitations of standard molecular mutation detection methods have historically precluded a genome-wide understanding of mutation rates and spectra in the nuclear genomes of multicellular organisms. We applied two high-throughput DNA sequencing technologies to identify and characterize hundreds of spontaneously arising base-substitution mutations in 10 Caenorhabditis elegans mutation-accumulation (MA)-line nuclear genomes. C. elegans mutation rate estimates were similar to previous calculations based on smaller numbers of m…