Search results for " Mito"
showing 10 items of 895 documents
Characterization of the length polymorphism in the A + T-rich region of the Drosophila obscura group species
1993
In the twelve Drosophila obscura group species studied, belonging to the affinis, obscura, and pseudoobscura subgroups, the mitochondrial DNA length ranges from 15.8 to 17.2 kb. This length polymorphism is mainly due to insertions/deletions in the variable region of the A + T-rich region. In addition, one species (D. tristis) possess a tandem duplication of a 470-bp fragment that contains the replication origin. The same duplication has occurred at least twice in the Drosophila evolutionary history due to the fact that the repetition is analogous to repetitions found in the four species of the D. melanogaster complex. By comparing the nucleotide sequence of the conserved region in D. ambigu…
Mitochondrial inheritance and fermentative : oxidative balance in hybrids between Saccharomyces cerevisiae and Saccharomyces uvarum.
2008
Breeding between Saccharomyces species is a useful tool for obtaining improved wine yeast strains, combining fermentative features of parental species. In this work, 25 artificial Saccharomyces cerevisiae × Saccharomyces uvarum hybrids were constructed by spore conjugation. A multi-locus PCR‐restriction fragment length polymorphism (PCR‐RFLP) analysis, targeting six nuclear gene markers and the ribosomal region including the 5.8S rRNA gene and the two internal transcribed spacers, showed that the hybrid genome is the result of two chromosome sets, one coming from S. cerevisiae and the other from S. uvarum. Mitochondrial DNA (mtDNA) typing showed uniparental inheritance in all hybrids. Furth…
New Insights Into Mitochondrial DNA Reconstruction and Variant Detection in Ancient Samples
2021
Ancient DNA (aDNA) studies are frequently focused on the analysis of the mitochondrial DNA (mtDNA), which is much more abundant than the nuclear genome, hence can be better retrieved from ancient remains. However, postmortem DNA damage and contamination make the data analysis difficult because of DNA fragmentation and nucleotide alterations. In this regard, the assessment of the heteroplasmic fraction in ancient mtDNA has always been considered an unachievable goal due to the complexity in distinguishing true endogenous variants from artifacts. We implemented and applied a computational pipeline for mtDNA analysis to a dataset of 30 ancient human samples from an Iron Age necropolis in Poliz…
The complete mitochondrial genome of Bactrocera biguttula (Bezzi) (Diptera: Tephritidae) and phylogenetic relationships with other Dacini
2018
Bactrocera biguttula is an African olive fruit fly that does not attack cultivated olives but rather develops in the fruits of wild species of Olea and Noronhia. The complete mitochondrial genome of an individual specimen was characterized in comparison to other Bactrocera. The phylogenetic relationships of B. biguttula with other Dacini were investigated, with special focus on B. oleae, an agricultural pest known to attack cultivated and wild olives. The sequence had a total length of 15,829 bp, and included the typical features of insect mitogenomes, similarly to the other Bactrocera analysed. Start codons included ATG, ATC, ATT, and TCG (in COI). The majority of stop codons (TAA) were fu…
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 (>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…