Search results for "PLOT"

Towards a Physical Map of the HLA Complex

1989

The human major histocompatibility (HLA) complex is located on the short arm of chromosome 6 in the 6p21.31→6p21.33 region (1,2). There are three clusters of genes, the HLA class I, II, and III regions. Whereas the class III loci are only moderately polymorphic (see (3) for review), the class I and II genes which encode cell surface glycoproteins show an extreme degree of polymorphism. There are a minimum of 17 class I loci (4) and at least 15 genes for class II alpha and beta chains (5). In addition, we (6) and others (7) have recently demonstrated that also the loci for tumor necrosis factor (TNFA) and lymphotoxin (TNFB) are part of the HLA complex [see also Ragoussis et al., this volume]…

Results of collaborative study regarding the standardization of the Y-linked STR system DYS385 by the European DNA Profiling (EDNAP) group.

1999

Y-chromosome linked short tandem repeat (STR) loci are inherited as a closely linked haplotype, which appears to remain stable in a given paternal lineage over many generations. In forensic cases, Y-linked STRs are particularly useful for the identification of human remains as well as in rape cases with mixed male/female stain samples. DYS385 is derived from tandemly duplicated segments of the Y chromosome thus giving rise to two fragments of variable length which do not behave like alleles but genotypes. The European DNA Profiling (EDNAP) group has carried out a collaborative exercise among 14 participating laboratories using DYS385 for typing of five unknown bloodstains and a control samp…

The STR252-IVS10nt546-VNTR7 phenylalanine hydroxylase minihaplotype in five Mediterranean samples.

1997

IVS10nt546 (IVS10nt-11g→a) is the most common molecular defect of the phenylalanine hydroxylase gene causing phenylketonuria in Mediterranean populations. Previous studies have proposed various and alternative hypotheses concerning the geographical origin and pattern of diffusion of this mutation in this area. In this study, this issue was re-examined on a large sample (149) of “Mediterranean” IVS10nt546 mutant alleles analysed with multiallelic intragenic polymorphisms. The analysis of intragenic microsatellite (STR) and minisatellite (VNTR) polymorphisms shows allelic heterogeneity of the IVS10nt546 mutation. Eight STR and three VNTR alleles were found in association with the splicing def…

The genetic structure of Drosophila subobscura populations from the islands of Majorca and Minorca (Balearic Islands, Spain) based on allozymes and m…

1999

The genetic structure of seven populations of Drosophila subobscura from different locations on Majorca and Minorca (Balearic Islands, Spain) was studied using two types of markers: allozyme and mitochondrial DNA restriction analyses. Both markers showed congruent results. In the allozyme data, when the Acph-1 locus was excluded from the joint FST statistics, only three out of 21 comparisons were statistically significant, lending support to the hypothesis of low genetic differentiation. The mtDNA restriction analyses showed two haplotypes at a high frequency (more than 40% each), irrespective of the location considered, and a number of endemic haplotypes at very low frequencies (not higher…

Congruence in genetic markers used to describe Mediterranean and Atlantic populations of European hake (Merluccius merluccius L. 1758)

2004

Summary Eight samples of the hake, Merluccius merluccius L., from the Mediterranean basin (370 fishes total) and one from the Atlantic ocean (50 fishes) were analysed in order to assess genetic variability and describe genetic population structure. Five polymorphic protein coding loci were scored (ADH*, PGI-1*, PGI-2*, PGM* and SOD-1*) in eight samples, together with a haplotype variation of four samples, obtained from polymerase chain reaction/restriction fragment length polymorphism (PCR–RFLP) analysis on the mitochondrial DNA control region. The average value for observed heterozygosity was typically higher than expected (showing an excess of heterozygotes among the samples) whereas the …

Lack of seasonal changes in mitochondrial DNA variability of a Drosophila subobscura population

1994

Restriction site analysis of mtDNA of 550 isofemale lines corresponding to different seasonal samples of a single geographic population of Drosophila subobscura was carried out. The distribution pattern of haplotypes was similar to that observed for the entire range of the species on the European continent: two haplotypes were equally and highly frequent, and a set of sporadic haplotypes were almost never present in more than one seasonal sampling. No statistically significant evidence was found for between-population heterogeneity across time, and the mean within-population variation was similar to other mtDNA restriction site analyses previously reported for D. subobscura populations. The…

Frequency of the HFE Gene Mutations in Five Italian Populations

2002

Abstract ABSTRACT Genetic hemochromatosis is an autosomal recessive disorder characterized by iron overload and a variety of clinical manifestations such as liver cirrhosis and arthropathy. It is the most common genetic disease of northern European populations. The principal gene responsible for hereditary hemochromatosis, designated HFE, is located on chromosome 6 in the HLA region. The single point mutation 845A, changing cysteine at position 282 to tyrosine (C282Y), in this gene has been identified as the main genetic basis of hereditary hemochromatosis. Two other mutations, 187G, a histidine to aspartate at amino acid 63 (H63D), and 193T, a serine to cysteine at amino acid 65 (S65C), ap…

A new polymorphism in the human HFE gene

1999

GENETIC POLYMORPHISM OF THE FOURTH COMPONENT OF HUMAN COMPLEMENT: POPULATION STUDY AND PROPOSAL FOR A REVISED NOMENCLATURE BASED ON GENOMIC PCR TYPIN…

1996

SUMMARY The fourth component of human complement (C4) is coded for by two homologous genes, C4A and C4B, located in the class III region of the major histocompatibility complex (MHC). Genetic typing of C4A and B alleles is routinely carried out by high-voltage agarose gel electrophoresis. The electrophoretic C4 polymorphism can be further subdivided by the Rodgers (Rg) and Chido (Ch) blood groups, which are antigenic determinants of the C4A and B alpha-chains, respectively. We have used a recently described direct PCR typing method using sequence-specific primers (PCR-SSP) in combination with electrophoretic C4 typing as well as genomic RFLP analysis to determine the frequency of C4 allotyp…

Prion protein gene frequencies in three Sicilian dairy sheep populations

2008

The objective of this paper was to investigate the prion protein (PrP) genotype and haplotype frequencies in three Sicilian dairy sheep populations. The three populations were: (1) 1096 Valle del Belice animals, (2) 1143 Comisana animals, and (3) 1771 individuals from 5 flocks with scrapie outbreaks, in which the animals were crossbreds derived from indigenous Sicilian dairy breeds. PrP genotypes are described for the three codons 136 (Alanine or Valine; A, V), 154 (Histidine or Arginine; H, R), and 171 (Glutamine, Arginine or Histidine; Q, R, H) which represent polymorphisms known to be linked with scrapie susceptibility. The Valle del Belice haplotype frequencies were 32.3% ARR, 6.5% AHQ,…