Search results for "population genetics."

Isolation and use of microsatellite loci in Melicertus kerathurus (Crustacea, Penaeidae).

2010

Melicertus kerathurus represents an economically important resource for fisheries and aquaculture. Seven microsatellite loci from 373 specimens of M. kerathurus collected in different parts of the Mediterranean and NE Atlantic were identified. Four of these microsatellites showed a moderate level of polymorphism, with 2 to 14 alleles per locus, whereas three had a monomorphic profile. Observed and expected heterozygosity ranged between 0.28 to0.64 and 0.28 to 0.65, respectively. Three microsatellite loci deviated from Hardy-Weinberg equilibrium in some populations, with a deficit of heterozygosity. Mean Fst values showed significant differentiation among sample sites analysed and indicate t…

A hierarchical analysis of genetic structure and variability in patchily distributed coexisting Chiastocheta species (Diptera:Anthomyiidae)

1996

The pattern of genetic variation in four coexisting fly species of the genus Chiastocheta was studied by allozyme electrophoresis. The fly species are confined to patches of one plant, Trollius europaeus, and thus experience very similar habitat fluctuations. Collection sites were chosen in a hierarchical fashion and F-statistics were estimated at three levels: intraregion, inter-region and total population. Population characteristic genetic parameters were compared within and among species and were related to the hierarchical level. The species were used as replicate experiments for inference of habitat history, and the hierarchical levels were used as inference for specific gene flow patt…

PCR-Typing of the Human HLA-DQα Locus: Population Genetics and Application in Forensic Casework

1991

Multi- and single-locus probes recognizing highly polymorphic DNA sequences throughout the genome ([1–3]; C. Rittner, this volume) have become powerful tools for paternity testing and forensic stain analysis. In forensic casework, however, DNA probe technology can often not be applied, since genomic DNA extracted from stain material exposed to conditions of high temperatures and humidity is degraded. Also, the amount of DNA to be typed may not be sufficient to use DNA probe technology, e.g. if extracted from minute blood or sperm stains, from single hairs or from cell smears on microscope slides.

Y-chromosomal STR haplotypes in Sicily

2006

Eight Y-chromosomal short tandem repeats (STRs)-DYS19, DYS389-I, DYS389-II, DYS390, DYS391, DYS392, DYS393 and DYS385 - were typed in a population sample (n = 255) of unrelated Sicilian males from nine different towns on the main island and from the island of Pantelleria. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Polymorphisms of inversions and Adh alleles in eye colour mutant experimental populations of Drosophila melanogaster

1987

Genetic Variability of Hepatitis C Virus before and after Combined Therapy of Interferon plus Ribavirin

2008

We present an analysis of the selective forces acting on two hepatitis C virus genome regions previously postulated to be involved in the viral response to combined antiviral therapy. One includes the three hypervariable regions in the envelope E2 glycoprotein, and the other encompasses the PKR binding domain and the V3 domain in the NS5A region. We used a cohort of 22 non-responder patients to combined therapy (interferon alpha-2a plus ribavirin) for which samples were obtained before initiation of therapy and after 6 or/and 12 months of treatment. A range of 25-100 clones per patient, genome region and time sample were sequenced. These were used to detect general patterns of adaptation, t…

Evidence of Recombination in Intrapatient Populations of Hepatitis C Virus.

2008

Hepatitis C virus (HCV) is a major cause of liver disease worldwide and a potential cause of substantial morbidity and mortality in the future. HCV is characterized by a high level of genetic heterogeneity. Although homologous recombination has been demonstrated in many members of the family Flaviviridae, to which HCV belongs, there are only a few studies reporting recombination on natural populations of HCV, suggesting that these events are rare in vivo. Furthermore, these few studies have focused on recombination between different HCV genotypes/subtypes but there are no reports on the extent of intra-genotype or intra-subtype recombination between viral strains infecting the same patient.…

The climatic and genetic heritage of Italian goat breeds with genomic SNP data

2021

Local adaptation of animals to the environment can abruptly become a burden when faced with rapid climatic changes such as those foreseen for the Italian peninsula over the next 70 years. Our study investigates the genetic structure of the Italian goat populations and links it with the environment and how genetics might evolve over the next 50 years. We used one of the largest national datasets including > 1000 goats from 33 populations across the Italian peninsula collected by the Italian Goat Consortium and genotyped with over 50 k markers. Our results showed that Italian goats can be discriminated in three groups reflective of the Italian geography and its geo-political situation prec…

Effects of Large-Scale Releases on the Genetic Structure of Red Sea Bream (Pagrus major, Temminck et Schlegel) Populations in Japan.

2014

Large-scale hatchery releases are carried out for many marine fish species worldwide; nevertheless, the long-term effects of this practice on the genetic structure of natural populations remains unclear. The lack of knowledge is especially evident when independent stock enhancement programs are conducted simultaneously on the same species at different geographical locations, as occurs with red sea bream (Pagrus major, Temminck et Schlegel) in Japan. In this study, we examined the putative effects of intensive offspring releases on the genetic structure of red sea bream populations along the Japanese archipelago by genotyping 848 fish at fifteen microsatellite loci. Our results suggests weak…

Genome-Wide SNP-Genotyping Array to Study the Evolution of the Human Pathogen Vibrio vulnificus Biotype 3

2014

Vibrio vulnificus is an aquatic bacterium and an important human pathogen. Strains Of V. vulnificus are classified into three different biotypes. The newly emerged biotype 3 has been found to be clonal and restricted to Israel. In the family Vibrionaceae , horizontal gene transfer is the main mechanism responsible for the emergence of new pathogen groups. To better understand the evolution of the bacterium, and in particular to trace the evolution of biotype 3, we performed genome-wide SNP genotyping of 254 clinical and environmental V. vulnificus isolates with worldwide distribution recovered over a 30-year period, representing all phylogeny groups. A custom single-nucleotide polymorphism …