Search results for "Haplotype"
showing 10 items of 444 documents
Population history in social spiders repeated: colony structure and lineage evolution inStegodyphus mimosarum(Eresidae)
2009
Social cooperative spiders from diverse taxonomic families share life-history and demographic traits, including highly inbred colony structure. The combination of traits suggests constrained pathways for social evolution in spiders. The genus Stegodyphus has three independently evolved social species, which can be used as replicate samples to analyse population constraints in evolutionary time. We tested colony structure and population history of the social S. mimosarum from South and East Africa using mitochondrial DNA variation, and we compared the results to published data for the independently evolved social congener S. dumicola. S. mimosarum had many and diverse haplotypes (5-7% sequen…
Molecular characterization and cytonuclear disequilibria of two Drosophila subobscura mitochondrial haplotypes.
1993
According to restriction site analyses of mitochondrial DNA, Drosophila subobscura shows a polymorphism that consists of two frequent haplotypes that are evenly distributed all over the Old World and several rare haplotypes never present in more than one locality. To ascertain the causes responsible for such distribution, three different mtDNA fragments from haplotypes I and II sampled in a population from Zürich have been partially sequenced. Only three silent nucleotide changes have been detected in the ND5 gene. One of them implies the loss of the HaeIII restriction site, which differentiates haplotype I from haplotype II. On the basis of these results as well as on others involving the…
Mitochondrial DNA haplotype frequencies in natural and experimental populations of Drosophila subobscura.
1998
Abstract The evolution of Drosophila subobscura mitochondrial DNA has been studied in experimental populations, founded with flies from a natural population from Esporles (Majorca, Balearic Islands, Spain). This population, like other European ones, is characterized by the presence of two very common (>96%) mitochondrial haplotypes (called I and II) and rare and endemic haplotypes that appear at very low frequencies. There is no statistical evidence of positive Darwinian selection acting on the mitochondrial DNA variants according to Tajima's neutrality test. Two experimental populations, with one replicate each, were established with flies having a heterogeneous nuclear genetic back…
Genetic divergence between morphological forms of brown troutSalmo truttaL. in the Balkan region of Macedonia
2010
The objective of this study was to characterize the genetic structure of two Balkan brown trout morphotypes, Salmo macedonicus and Salmo pelagonicus, and to test whether molecular traits support the species’ status proposed by traditional morphological identification. The mitochondrial DNA 12S-rDNA, cyt b and control region genes were sequenced in 15 specimens collected from three localities in the Former Yugoslav Republic of Macedonia. The results of these markers did not support the taxonomic category of species but confirmed the existence of two morphotypes, Salmo trutta macedonicus and Salmo trutta pelagonicus, in the Aegean–Adriatic lineages of the Salmo trutta species complex.
A Revised Timescale for Human Evolution Based on Ancient Mitochondrial Genomes
2013
Summary Background Recent analyses of de novo DNA mutations in modern humans have suggested a nuclear substitution rate that is approximately half that of previous estimates based on fossil calibration. This result has led to suggestions that major events in human evolution occurred far earlier than previously thought. Results Here, we use mitochondrial genome sequences from ten securely dated ancient modern humans spanning 40,000 years as calibration points for the mitochondrial clock, thus yielding a direct estimate of the mitochondrial substitution rate. Our clock yields mitochondrial divergence times that are in agreement with earlier estimates based on calibration points derived from e…
Early history of European domestic cattle as revealed by ancient DNA
2006
We present an extensive ancient DNA analysis of mainly Neolithic cattle bones sampled from archaeological sites along the route of Neolithic expansion, from Turkey to North-Central Europe and Britain. We place this first reasonable population sample of Neolithic cattle mitochondrial DNA sequence diversity in context to illustrate the continuity of haplotype variation patterns from the first European domestic cattle to the present. Interestingly, the dominant Central European pattern, a starburst phylogeny around the modal sequence, T3, has a Neolithic origin, and the reduced diversity within this cluster in the ancient samples accords with their shorter history of post-domestic accumulation…
Identification and potential origin of invasive clawed frogsXenopus(Anura: Pipidae) in Sicily based on mitochondrial and nuclear DNA
2013
African clawed frogs of the widespread polytypic species Xenopus laevis Daudin, 1802 (ranging large parts of sub-Saharan Africa) have been spreading since the 1940s, and have established reproductive populations in Europe, Asia and the Americas, where they can have negative impact as competitors of native amphibians and as disease vectors for chytridomycosis or ranaviruses. Here we use two mitochondrial (cytochrome b, 16S rDNA) and one nuclear (RAG 1: Recombination Associated Gene 1) DNA markers to infer the potential origin of invasive clawed frogs from Sicily that represent the largest invasive population in Europe. Identical mtDNA haplotypes match with those of Xenopus laevis, and Sicili…
The origin of Swedish and Norwegian populations of the Eurasian harvest mouse (Micromys minutus).
2012
The harvest mouse (Micromys minutus) occurs throughout most of continental Europe. There are also two isolated and recently discovered populations on the Scandinavian peninsula, in Sweden and Norway. Here, we investigate the origin of these populations through analyses of mitochondrial DNA. We found that the two populations on the Scandinavian peninsula have different mtDNA haplotypes. A comparison of our haplotypes to published sequences from most of Europe showed that all Swedish and Norwegian haplotypes are most closely related to the haplotypes in harvest mice from Denmark. Hence, the two populations seem to represent independent colonisations but originate from the same geographical ar…
Fitness and life-history traits of the two major mitochondrial DNA haplotypes of Drosophila subobscura
2004
Mitochondrial DNA restriction site analyses on natural populations of Drosophila subobscura have proved the existence of two common, coexisting haplotypes (I and II), as well as a set of less frequent ones derived from them. To explain this distribution, experiments to date point practically to all possible genetic mechanisms being involved in the changes of gene frequencies (cytonuclear coadaptation, direct natural selection on mtDNA and genetic drift). In an attempt to find differences that help to understand the dynamics of these haplotypes and to detect the effect of selection, we measured certain fitness components and life-history traits (egg-larva and larva-adult viabilities and deve…
DNA Multi-Marker Genotyping and CIAS Morphometric Phenotyping of Fasciola gigantica-Sized Flukes from Ecuador, with an Analysis of the Radix Absence …
2021
Simple Summary Fasciolid flukes collected from sheep and cattle in Ecuador showed a high diversity in DNA sequences whose analyses indicated introductions from South America, European and North American countries. These results agree with the numerous livestock importations performed by Ecuador. Abnormally big-sized liver flukes were found in Ecuadorian sheep. The morphometric phenotypic CIAS study showed that its size maximum and mean very pronouncedly and significantly surpassed those of the Fasciola hepatica populations from South America and Spain and proved to be intermediate between standard F. hepatica and F. gigantica populations. Such a feature is only known in intermediate fasciol…