Search results for "mitochondrial dna"

Asymmetric allelic introgression across a hybrid zone of the coal tit (Periparus ater) in the central Himalayas*

2021

Abstract In the Himalayas, a number of secondary contact zones have been described for vicariant vertebrate taxa. However, analyses of genetic divergence and admixture are missing for most of these examples. In this study, we provide a population genetic analysis for the coal tit (Periparus ater) hybrid zone in Nepal. Intermediate phenotypes between the distinctive western “spot‐winged tit” (P. a. melanolophus) and Eastern Himalayan coal tits (P. a. aemodius) occur across a narrow range of <100 km in western Nepal. As a peculiarity, another distinctive cinnamon‐bellied form is known from a single population so far. Genetic admixture of western and eastern mitochondrial lineages was restrict…

Diagnosis of sibling species of Drosophila involved in the colonization of North America by D. subobscura

1997

To determine the effects of the recent colonization of the west coast of North America by the Palaearctic species Drosophila subobscura on the dynamics of the Drosophila populations, the sibling species D. athabasca and D. azteca must be classified unambiguously. We have characterized these two species using three molecular techniques: allozymes, mtDNA and RAPDs. All three techniques allow the classification of any individual as belonging to either species. The study of five localities in northern California and southern Oregon show that the area of overlap is larger than previously described.

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 (&amp;gt;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…

The mitochondrial genome of fission yeast: inability of all introns to splice autocatalytically, and construction and characterization of an intronle…

1991

In this paper we report the inability of four group I introns in the gene encoding subunit I of cytochrome c oxidase (cox1) and the group II intron in the apocytochrome b gene (cob) to splice autocatalytically. Furthermore we present the characterization of the first cox1 intron in the mutator strain anar-14 and the construction and characterization of strains with intronless mitochondrial genomes. We provide evidence that removal of introns at the DNA level (termed DNA splicing) is dependent on an active RNA maturase. Finally we demonstrate that the absence of introns does not abolish homologous mitochondrial recombination.

Phylogeny of the Drosophila obscura species group deduced from mitochondrial DNA sequences

1994

Approximately 2 kb corresponding to different regions of the mtDNA of 14 different species of the obscura group of Drosophila have been sequenced. In spite of the uncertainties arising in the phylogenetic reconstruction due to a restrictive selection toward a high mtDNA A+T content, all the phylogenetic analysis carried out clearly indicate that the obscura group is formed by, at least, four well-defined lineages that would have appeared as the consequence of a rapid phyletic radiation. Two of the lineages correspond to monophyletic subgroups (i.e., affinis and pseudoobscura), whereas the obscura subgroup remains heterogeneous assemblage that could be reasonably subdivided into at least two…

Mitochondrial simple sequenze repeats and 12s – rRNA gene reveal two distinct lineages of Crocidura russula (Mammalia, Sorcidae)

2004

A short segment (135 bp) of the control region and a partial sequence (394 bp) of the 12S-rRNA gene in the mitochondrial DNA of Crocidura russula were analyzed in order to test a previous hypothesis regarding the presence of a gene flow disruption in northern Africa. This breakpoint would have separated northeast-African C. russula populations from the European (plus the northwest-African) populations. The analysis was carried out on specimens from Tunisia (C. r. cf agilis), Sardinia (C. r. ichnusae), and Pantelleria (C. r. cossyrensis), and on C. r. russula from Spain and Belgium. Two C. russula lineages were identified; they both shared R2 tandem repeated motifs of the same length (12 bp)…

Embryo ATP production can be modulated by maternal mitochondrial DNA secreted from the human endometrium in extracellular vesicles

2019

Platyzoan mitochondrial genomes.

2012

Platyzoa is a putative lophotrochozoan (spiralian) subtaxon within the protostome clade of Metazoa, comprising a range of biologically diverse, mostly small worm-shaped animals. The monophyly of Platyzoa, the relationships between the putative subgroups Platyhelminthes, Gastrotricha and Gnathifera (the latter comprising at least Gnathostomulida, "Rotifera" and Acanthocephala) as well as some aspects of the internal phylogenies of these subgroups are highly debated. Here we review how complete mitochondrial (mt) genome data contribute to these debates. We highlight special features of the mt genomes and discuss problems in mtDNA phylogenies of the clade. Mitochondrial genome data seem to be …