Search results for "Polymorphism"

Positive selection at codon 38 of the human KCNE1 (= minK) gene and sporadic absence of 38Ser-coding mRNAs in Gly38Ser heterozygotes

2009

Abstract Background KCNE1 represents the regulatory beta-subunit of the slowly activating delayed rectifier potassium channel (IKs). Variants of KCNE1 have repeatedly been linked to the long-QT syndrome (LQTS), a disorder which predisposes to deafness, ventricular tachyarrhythmia, syncope, and sudden cardiac death. Results We here analyze the evolution of the common Gly38Ser variant (rs1805127), using genomic DNAs, complementary DNAs, and HEK293-expressed variants of altogether 19 mammalian species. The between species comparison reveals that the human-specific Gly38Ser polymorphism evolved under strong positive Darwinian selection, probably in adaptation to specific challenges in the fine-…

Genetic Characterization of Legionella pneumophila Isolated from a Common Watershed in Comunidad Valenciana, Spain

2013

Legionella pneumophila infects humans to produce legionellosis and Pontiac fever only from environmental sources. In order to establish control measures and study the sources of outbreaks it is essential to know extent and distribution of strain variants of this bacterium in the environment. Sporadic and outbreak-related cases of legionellosis have been historically frequent in the Comunidad Valenciana region (CV, Spain), with a high prevalence in its Southeastern-most part (BV). Environmental investigations for the detection of Legionella pneumophila are performed in this area routinely. We present a population genetics study of 87 L. pneumophila strains isolated in 13 different localities…

On the complexity of the Saccharomyces bayanus taxon: Hybridization and potential hybrid speciation

2014

Although the genus Saccharomyces has been thoroughly studied, some species in the genus has not yet been accurately resolved; an example is S. bayanus, a taxon that includes genetically diverse lineages of pure and hybrid strains. This diversity makes the assignation and classification of strains belonging to this species unclear and controversial. They have been subdivided by some authors into two varieties (bayanus and uvarum), which have been raised to the species level by others. In this work, we evaluate the complexity of 46 different strains included in the S. bayanus taxon by means of PCR-RFLP analysis and by sequencing of 34 gene regions and one mitochondrial gene. Using the sequenc…

Reconstruction of the evolutionary history of Saccharomyces cerevisiae x S. kudriavzevii hybrids based on multilocus sequence analysis.

2012

In recent years, interspecific hybridization and introgression are increasingly recognized as significant events in the evolution of Saccharomyces yeasts. These mechanisms have probably been involved in the origin of novel yeast genotypes and phenotypes, which in due course were to colonize and predominate in the new fermentative environments created by human manipulation. The particular conditions in which hybrids arose are still unknown, as well as the number of possible hybridization events that generated the whole set of natural hybrids described in the literature during recent years. In this study, we could infer at least six different hybridization events that originated a set of 26 S…

The presence of FSH receptor polymorphism -29 G>A is associated with poor ovarian response in IVF/ICSI cycles

2014

A Genome-Wide Detection of Copy Number Variations Using SNP Genotyping Arrays in Braque Français Type Pyrénées Dogs

2019

Simple Summary Copy number variations (CNVs) are important sources of variation in mammalian species. In this study, we used a single nucleotide polymorphisms (SNP) array to detect CNVs in Braque Français, type Pyrénées dogs (BRA). Results overlapped moderately in comparison with previous studies on CNVs in dogs, leading to the identification of 16 novel CNVRs. Several genes were annotated in the CNV regions (CNVRs) detected, some of which related to muscle structure development. This breed is known to be excellent upland game birds dogs. The selection for such hunting behavior could have driven the presence of these genes into the CNVRs. Copy number variations may be of interest to study a…

Localization of non-specific X-linked mental retardation gene (MRX73) to Xp22.2.

2001

Clinical and molecular studies are reported on a family (MRX73) of five males with non-specific X-linked mental retardation (XLMR). A total of 33 microsatellite and RFLP markers was typed. The gene for this XLMR condition was been linked to DXS1195, with a lod score of 2.36 at theta = 0. The haplotype and multipoint linkage analyses suggest localization of the MRX73 locus to an interval of 2 cM defined by markers DXS8019 and DXS365, in Xp22.2. This interval contains the gene of Coffin-Lowry syndrome (RSK2), where a missense mutation has been associated with a form of non-specific mental retardation. Therefore, a search for RSK2 mutations was performed in the MRX73 family, but no causal muta…

A PCR-RFLP assay for the distinction between Fasciola hepatica and Fasciola gigantica.

2002

Fascioliasis is of well-known veterinary importance and an increasing human health problem, with reported cases in the five continents. The causative agents, Fasciola hepatica and Fasciola gigantica, present geographical distributions, which overlap in many regions of Africa and Asia, and in which the differentiation of both species is usually difficult because of the many variations in their morphological characteristics. Moreover, in humans, liver fluke classification cannot be achieved by clinical, pathological, coprological or immunological methods. The differential diagnosis between F. hepatica and F. gigantica infection is very important because of their different transmission and epi…

Fetuin-A in elderly: effect of genotype on serum levels

2011

Fetuin-A is a circulating inhibitor of ectopic calcification in vivo; it is decreased in patients with chronic kidney disease and correlates with glomerular filtration rate in patients with coronary artery disease. However, serum levels of Fetuin-A has not been described in elderly. Aim of the study was to evaluate Fetuin-A serum levels together with AHSG T256S genotype in a population of healthy elderly. Serum fetuin-A levels were determined by ELISA. T256S polymorphism of AHSG gene was determined by PCR-RFLP. Serum Fetuin-A was 0,38 ± 0,13 g/l in the group composed by 206 healthy centenarians. Moreover, subjects with at least one S allele had lower Fetuin-A levels (P<001). Interestingly, …

Polymorphisms in ABC transporter genes and concentrations of mercury in newborns - Evidence from two Mediterranean birth cohorts

2014

Background: The genetic background may influence methylmercury (MeHg) metabolism and neurotoxicity. ATP binding cassette (ABC) transporters actively transport various xenobiotics across biological membranes. Objective: To investigate the role of ABC polymorphisms as modifiers of prenatal exposure to MeHg. Methods: The study population consisted of participants (n = 1651) in two birth cohorts, one in Italy and Greece (PHIME) and the other in Spain (INMA). Women were recruited during pregnancy in Italy and Spain, and during the perinatal period in Greece. Total mercury concentrations were measured in cord blood samples by atomic absorption spectrometry. Maternal fish intake during pregnancy w…