Search results for "Allele frequency"

Forensic animal DNA typing: Allele nomenclature and standardization of 14 feline STR markers

2014

Since the domestic cat (Felis catus) has become one of the most popular pets and owners usually develop a close relationship to their cats, it is necessary to take traces of cats into account for forensic casework. For this purpose feline short tandem (STR) repeat markers have been investigated in several earlier studies, but no detailed description of sequence data, allelic variations or a repeat-based nomenclature is available. The aim of the study was to provide a suggestion for the allele nomenclature of 14 cat STR markers according to the recommendations of the International Society for Forensic Genetics (ISFG) for human DNA typing and to present a standardized system for a secure DNA …

Sex-dependent genetic markers of CYP3A4 expression and activity in human liver microsomes

2007

Objective: To find genetic markers of the individual cytochrome P450 (CYP)3A expression. Methods: A large collection of liver samples phenotyped for CYP3A expression and activity was genotyped for CYP3A variants. Data were analyzed for associations between CYP3A phenotypes and genotypes, and for evidence of recent selection. Results: We report associations between the hepatic CYP3A4 protein expression level, as well as its enzymatic activity, measured as verapamil N-dealkylation, and genetic polymorphisms from two regions within the CYP3A gene cluster. One region is defined by several variants, mostly located within CYP3A7, the other by a single nucleotide polymorphism in intron 7 of CYP3A…

Autosomal microsatellite and mtDNA genetic analysis in Sicily (Italy).

2003

DNA samples from 465 blood donors living in 7 towns of Sicily, the largest island of Italy, have been collected according to well defined criteria, and their genetic heterogeneity tested on the basis of 9 autosomal microsatellite and mitochondrial DNA polymorphisms for a total of 85 microsatellite allele and 10 mtDNA haplogroup frequencies. A preliminary account of the results shows that: a) the samples are genetically heterogeneous; b) the first principal coordinates of the samples are correlated more with their longitude than with their latitude, and this result is even more remarkable when one outlier sample (Butera) is not considered; c) distances among samples calculated from allele an…

The Origins of Lactase Persistence in Europe

2009

Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (−13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the −13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model w…

2018

In the recent past, sequencing of ancient human genomes has become increasingly common, leading to an immense amount of data to be explored. For this study we focused on comparing a set of ancient individuals with modern populations on behalf of markers for celiac disease. We analyzed a panel of 64 SNPs related to this disease, trying to detect changes in allele frequencies between ancient and modern individuals. We hope to make a contribution to the subject of genetic health throughout human history.

Second generation sequencing of three STRs D3S1358, D12S391 and D21S11 in Danes and a new nomenclature for sequenced STR alleles

2014

Second generation sequencing (SGS) may revolutionize the field of forensic STR typing. Two of the essential requirements for implementation of an SGS based approach for forensic investigations are (1) establishment of adequate frequency databases and (2) adoption of a new STR nomenclature. We report the STR sequences and allele frequencies of three STR loci: D3S1358, D12S391 and D21S11 in 197 unrelated Danes. We used a new STR nomenclature that depicts the locus name used in forensic genetics, the length of the repeat region divided by the repeat length (typically 4 nucleotides) and detailed sequence information of possible sub-repeats and SNPs within the amplified fragment.

Investigations on the genetics and population genetics of the ?2 polymorphism

1970

The results of studies on 49 families with 107 children and various populations of Caucasoid, Negroid and Mongoloid origin concerning the genetics and population genetics of the β2-glycoprotein I polymorphism are reported. In general the genetical model proposed by Cleve (1968) is confirmed: two autosomal alleles BgN and BgD controlling the phenotypes Bg N-N, Bg N-D and Bg D-D. However, divergences from this model were found in two families. They indicate the assumption of non-genetic factors influencing the phenotype expression rather than more complicated genetical control mechanisms. Within Caucasoid populations phenotype and gene frequencies show almost a homogeneous distribution. This …

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…

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;…

Unmasking frequency-dependent selection in tri-cultures of Drosophila melanogaster.

1989

Larval-to-adult viability was measured for three strains of Drosophila melanogaster: a wild strain and two eye colour mutant strains (cardinal and sepia) starting from seventy different genotypic compositions. Analyses of a sub-set of the data (not considering all genotypic frequencies) demonstrate frequency-dependence in the three strains. These results suggest that in this experiment, frequency-dependent selection may be masked by other selective forces, only being apparent when specific analyses are carried out.