Search results for "haplotypes"
showing 10 items of 295 documents
First phenotypic and genotypic description of Fasciola hepatica infecting highland cattle in the state of Mexico, Mexico
2018
Abstract Fascioliasis is a plantborne and zoonotic parasitic disease caused by fasciolid liver flukes. Fasciola hepatica is the only fasciolid species described in the Americas. Human fascioliasis endemic areas are mainly located in high altitude areas of the Americas. Given the necessity to characterize F. hepatica populations involved, the phenotypic and genotypic features of fasciolid adults infecting cattle in the highland area of Toluca, State of Mexico, Mexico, were analyzed and compared to fasciolid materials from the Northern Bolivian Altiplano, representing the altiplanic transmission pattern in a hyperendemic scenario. A computer image analysis system (CIAS) was applied on the bas…
Mitochondrial introgression suggests extensive ancestral hybridization events among Saccharomyces species.
2017
Horizontal gene transfer (HGT) in eukaryotic plastids and mitochondrial genomes is common, and plays an important role in organism evolution. In yeasts, recent mitochondrial HGT has been suggested between S. cerevisiae and S. paradoxus. However, few strains have been explored given the lack of accurate mitochondrial genome annotations. Mitochondrial genome sequences are important to understand how frequent these introgressions occur, and their role in cytonuclear incompatibilities and fitness. Indeed, most of the Bateson-Dobzhansky-Muller genetic incompatibilities described in yeasts are driven by cytonuclear incompatibilities. We herein explored the mitochondrial inheritance of several wor…
Female-specific association among I, J and K mitochondrial genetic haplogroups and cancer:A longitudinal cohort study
2018
Recent studies highlighted the role of mitochondrial dysregulation in cancer, suggesting that the different mitochondrial haplogroups might play a role in tumorigenesis and risk of cancer development. Our aim is to investigate whether any mitochondrial haplogroups carried a significant higher risk of cancer development in a large prospective cohort of North American people. The haplogroup assignment was performed by a combination of sequencing and PCR-RFLP techniques. Our specific outcome of interest was the incidence of any cancer during follow-up period. Overall, 3222 participants were included in the analysis. Women having I, J, K haplogroup reported a significant higher incidence of can…
Multilocus microsatellite analysis of European and African Candida glabrata isolates
2016
This study aimed to elucidate the genetic relatedness and epidemiology of 127 clinical and environmental Candida glabrata isolates from Europe and Africa using multilocus microsatellite analysis. Each isolate was first identified using phenotypic and molecular methods and subsequently, six unlinked microsatellite loci were analyzed using automated fluorescent genotyping. Genetic relationships were estimated using the minimum-spanning tree (MStree) method. Microsatellite analyses revealed the existence of 47 different genotypes. The fungal population showed an irregular distribution owing to the over-representation of genetically different infectious haplotypes. The most common genotype was …
Comprehensive Screening for Naturally Occurring Hepatitis C Virus Resistance to Direct-Acting Antivirals in the NS3, NS5A, and NS5B Genes in Worldwid…
2015
ABSTRACTThere is no comprehensive study available on the natural hepatitis C virus (HCV) polymorphism in sites associated with resistance including all viral genotypes which may present variable susceptibilities to particular direct-acting antivirals (DAAs). This study aimed to analyze the frequencies, genetic barriers, and evolutionary histories of naturally occurring resistance-associated variants (RAVs) in the six main HCV genotypes. A comprehensive analysis of up to 103 RAVs was performed in 2,901, 2,216, and 1,344 HCV isolates for the NS3, NS5A, and NS5B genes, respectively. We report significant intergenotypic differences in the frequencies of natural RAVs for these three HCV genes. I…
How to deal with Haplotype data: An Extension to the Conceptual Schema of the Human Genome
2016
[EN] The goal of this work is to describe the advantages of the application of Conceptual Modeling (CM) in complex domains, such as genomics. Nowadays, the study and comprehension of the human genome is a major challenge due to its high level of complexity. The constant evolution in the genomic domain contributes to the generation of ever larger amounts of new data, which means that if we do not manage it correctly data quality could be compromised (i.e., problems related with heterogeneity and inconsistent data). In this paper, we propose the use of a Conceptual Schema of the Human Genome (CSHG), designed to understand and improve our ontological commitment to the domain and also extend (e…
Global diversity in the TAS2R38 bitter taste receptor: revisiting a classic evolutionary PROPosal
2016
AbstractThe ability to taste phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) is a polymorphic trait mediated by the TAS2R38 bitter taste receptor gene. It has long been hypothesized that global genetic diversity at this locus evolved under pervasive pressures from balancing natural selection. However, recent high-resolution population genetic studies of TAS2Rs suggest that demographic events have played a critical role in the evolution of these genes. We here utilized the largest TAS2R38 database yet analyzed, consisting of 5,589 individuals from 105 populations, to examine natural selection, haplotype frequencies and linkage disequilibrium to estimate the effects of both selectio…
Biological Basis of the HLA-B8,DR3-Associated Progression of Acquired Immune Deficiency Syndrome
1998
The factors influencing the evolution of human immunodeficiency virus (HIV) infection are not fully known, but the host genotype undoubtedly plays a role in determining the outcome of the disease by affecting the immune response to HIV. The role of the host human leukocyte antigen (HLA) genotype in the regulation of susceptibility to HIV infection and expression has been studied extensively in different major risk groups. Certain HLA alleles and haplotypes, being associated with aberrant immune responses independently from HIV infection, have been reported to facilitate the rapid progression of disorders related to HIV infection. Particularly, the association of rapid acquired immunodeficie…
T-cell activation in HLA-B8,DR3-positive individuals early antigen expression defect in vitro
1995
The HLA-B8, DR3 haplotype is overrepresented in several autoimmune diseases, implying that genes predisposing to these disorders are linked to this haplotype. In the patients affected by these diseases, as well as in healthy HLA-B8, DR3 individuals, various dysfunctions reflecting an impairment of T-cell activation have been found. To better characterize T-cell impairment of HLA-B8, DR3-positive healthy individuals, we analyzed the surface expression of early (CD69) and late (CD71) activation phenotypes. MNC cultures were stimulated with PHA and used for T-cell phenotyping by flow cytometry analysis. The results showed that the percentage of CD69+ T cells was significantly decreased in MNC …
Role of APOBEC3H in the Viral Control of HIV Elite Controller Patients
2017
Background APOBEC3H (A3H) gene presents variation at 2 positions (rs139297 and rs79323350) leading to a non-functional protein. So far, there is no information on the role played by A3H in spontaneous control of HIV. The aim of this study was to evaluate the A3H polymorphisms distribution in a well-characterized group of Elite Controller (EC) subjects. Methods We analyzed the genotype distribution of two different SNPs (rs139297 and rs79323350) of A3H in 30 EC patients and compared with 11 non-controller (NC) HIV patients. Genotyping was performed by PCR, cloning and Sanger sequencing. Both polymorphisms were analyzed jointly in order to adequately attribute the active or inactive status of…