Search results for "Allele"

Genetic diversity in theCentaurea cinerariagroup (Compositae) in Sicily using isozymes

2006

Abstract The genetic diversity of seven taxa endemic to Sicily, C. cineraria, C. busambarensis, C. ucriae subsp. ucriae, C. ucriae subsp. umbrosa, C. todari, C. erycina and C. saccensis, from 11 localities was investigated using isozymes. Eight loci from five enzyme systems (IDH, MDH, PGD, PGM and PGI) were examined. A total of 19 alleles were identified, some rare and two of them exclusive to different populations. The allelic frequencies and the genetic variability values for each population were calculated. On the whole, the genetic diversity, i.e., average polymorphism (P) = 0.41, average number of alleles per locus (A) = 1.75, Nei's gene diversity (H) = 0.18, is moderate, with the high…

Population structure of a parasitic plant and its perennial host

2002

Characterization of host and parasite population genetic structure and estimation of gene flow among populations are essential for the understanding of parasite local adaptation and coevolutionary interactions between hosts and parasites. We examined two aspects of population structure in a parasitic plant, the greater dodder (Cuscuta europaea) and its host plant, the stinging nettle (Urtica dioica), using allozyme data from 12 host and eight parasite populations. First, we examined whether hosts exposed to parasitism in the past contain higher levels of genetic variation. Second, we examined whether host and parasite populations differ in terms of population structure and if their populati…

Effect of the IL28B Rs12979860 C/T polymorphism on the incidence and features of active cytomegalovirus infection in allogeneic stem cell transplant …

2013

The current study was aimed at investigating whether the single nucleotide polymorphism (SNP) (rs12979860), upstream of the IL28B gene, had any effect on the incidence rate and the features of active CMV infection in the Allogeneic stem cell transplantation setting. This was a retrospective observational study including 151 patients undergoing T cell-replete Allo-SCT. Donor and recipient IL28 SNP genotype was determined by allele-specific real-time PCR. The incidence rate of active CMV infection was not significantly associated with either the donor or the recipient IL28B SNP genotype. Nevertheless, a trend towards a lower incidence of active CMV infection was noted in the donor T/T populat…

Genetic population structure of two cryptic Gammarus fossarum types across a contact zone

1998

Previous studies have revealed inconsistent results about the taxonomic status of European Gammarus fossarum forms. The variability in morphology and hybridization ability has not shown clear geographic patterns, whereas on a genetical basis two Central European G. fossarum forms have been proposed. In the present study the genetic structure of G. fossarum populations was investigated across a natural contact zone. For the first time direct comparisons of allotopic versus syntopic populations were feasible. 24 Populations of G. fossarum plus 4 populations of G. pulex (as outgroup) were sampled along 2 transects across the contact zone. The genotypes of about 60 individuals per population we…

Fibrinogen plasma levels in an apparently healthy general population: Relation to environmental and genetic determinants

1998

SummaryElevated fibrinogen levels are an independent risk factor for cardiovascular ischemic disease. We investigated the relationship between cardiovascular ischemic risk factors, the fibrinogen Bβ-chain G/A-455 polymorphism and plasma fibrinogen levels in 989 apparently healthy subjects. Fibrinogen values were higher in subjects with C reactive protein (C-RP) > 0.33 mg/dl, BMI > 23.9 kg/m2, total cholesterol > 4.84 mmol/l, triglycerides >1.02 mmol/l, PAI-1 antigen >12.2 ng/ml, carriers of the A allele, first-degree relative history of coronary artery disease, or consuming >10 cigarettes per day (p <0.01). Men and ethanol drinkers showed lower plasma fibrinogen levels …

HLA DQA1 and D1S80 in the Population of Valencia (Spain)

1996

EZH2 mutations are frequent and represent an early event in follicular lymphoma

2013

Gain of function mutations in the H3K27 methyltransferase EZH2 represent a promising therapeutic target in germinal center lymphomas. In this study, we assessed the frequency and distribution of EZH2 mutations in a large cohort of patients with follicular lymphoma (FL) (n = 366) and performed a longitudinal analysis of mutation during the disease progression from FL to transformed FL (tFL) (n = 33). Mutations were detected at 3 recurrent mutation hot spots (Y646, A682, and A692) in 27% of FL cases with variant allele frequencies (VAF) ranging from 2% to 61%. By comparing VAF of EZH2 with other mutation targets (CREBBP, MLL2, TNFRSF14, and MEF2B), we were able to distinguish patients harbori…

Anther culture in Citrus clementina: a way to regenerate tri-haploids

2005

Abstract. Regenerants from anther culture of Citrus clementina Hort. ex Tan. cvv. Nules, SRA 63, and Monreal were obtained in different experiments from 1994 to 2002. Genetic analysis of 37 such regenerants was carried out using 4 microsatellite markers that were heterozygous in the parental genotypes. The results showed that in all cases but one the regenerants carried only one or the other allele of the parental genotype, and were therefore homozygous and produced through a process of gametophytic embryogenesis. Ploidy analysis by flow cytometry of 94 regenerants showed that as many as 82% of them were tri-haploids, rather than haploids or doubled-haploids as expected, with other ploidy …

Regulatory cytokine gene polymorphisms and risk of colorectal carcinoma.

2006

It is well established that cancer arises in chronically inflamed tissue, and this is particularly notable in the gastrointestinal tract. Classic examples include Helicobacter pylori-associated gastric cancer, hepatocellular carcinoma, and inflammatory bowel disease-associated colorectal cancer. Growing evidence suggests that these associations might be not casual findings. Focusing on individual cytokines has generated evidence that anti-inflammatory cytokine interleukin (IL)-10 and transforming growth factor-beta1 (TGF-beta1) may have a complex role in gastrointestinal carcinogenesis. As an example, IL-10-deficient mice develop severe atrophic gastritis and a chronic enterocolitis, develo…

Stable polymorphism for mutant eye colour geues in populations of Drosophila melanogaster in two different media

1988

In previous work analyzing variability of eye colour alleles existing in natural populations of D. melanogaster, it was observed that the number of females heterozygous for some eye colour alleles was greater in a wine cellar population than in populations outside this cellar. In order to determine which mechanisms caused these eye colour alleles to be favored in the heterozygotes, the changes in the frequency of four eye colour alleles frequently seen in the cellar population (se77o, sf77m, cd77o and multichromosomal 77o) was studied in artificial populations. Two different culture media, one supplemented with 10% ethanol and the other without ethanol were used. It was found that each of t…