Search results for "MITOCHONDRIAL"
showing 10 items of 919 documents
Investigation of deltamethrin resistance in salmon lice (Lepeophtheirus salmonis) provides no evidence for roles of mutations in voltage-gated sodium…
2020
BACKGROUND The pyrethroid deltamethrin is used to treat infestations of farmed salmon by parasitic salmon lice, Lepeophtheirus salmonis (Kroyer). However, the efficacy of deltamethrin for salmon delousing is threatened by resistance development. In terrestrial arthropods, knockdown resistance (kdr) mutations of the voltage-gated sodium channel (Nav ), the molecular target for pyrethroids, can cause deltamethrin resistance. A putative kdr mutation of an L. salmonis sodium channel homologue (LsNav 1.3 I936V) has been identified previously. At the same time, deltamethrin resistance of L. salmonis has been shown to be inherited maternally and to be associated with mitochondrial DNA (mtDNA) muta…
Introgression of mitochondrial DNA among Myodes voles: consequences for energetics?
2011
Abstract Background Introgression of mitochondrial DNA (mtDNA) is among the most frequently described cases of reticulate evolution. The tendency of mtDNA to cross interspecific barriers is somewhat counter-intuitive considering the key function of enzymes that it encodes in the oxidative-phosphorylation process, which could give rise to hybrid dysfunction. How mtDNA reticulation affects the evolution of metabolic functions is, however, uncertain. Here we investigated how morpho-physiological traits vary in natural populations of a common rodent (the bank vole, Myodes glareolus) and whether this variation could be associated with mtDNA introgression. First, we confirmed that M. glareolus ha…
Genomic Analysis of European Drosophila melanogaster Populations Reveals Longitudinal Structure, Continent-Wide Selection, and Previously Unknown DNA…
2020
Genetic variation is the fuel of evolution, with standing genetic variation especially important for short-term evolution and local adaptation. To date, studies of spatiotemporal patterns of genetic variation in natural populations have been challenging, as comprehensive sampling is logistically difficult, and sequencing of entire populations costly. Here, we address these issues using a collaborative approach, sequencing 48 pooled population samples from 32 locations, and perform the first continent-wide genomic analysis of genetic variation in European Drosophila melanogaster. Our analyses uncover longitudinal population structure, provide evidence for continent-wide selective sweeps, ide…
Helminth communities of loggerhead turtles (Caretta caretta) from Central and Western Mediterranean Sea: the importance of host's ontogeny.
2009
We investigated the factors providing structure to the helminth communities of 182 loggerhead sea turtles, Caretta caretta, collected in 6 localities from Central and Western Mediterranean. Fifteen helminth taxa (10 digeneans, 4 nematodes and 1 acanthocephalan) were identified, of which 12 were specialist to marine turtles; very low numbers of immature individuals of 3 species typical from fish or cetaceans were also found. These observations confirm the hypothesis that phylogenetic factors restrict community composition to helminth species specific to marine turtles. There were significant community dissimilarities between turtles from different localities, the overall pattern being compat…
Sporadic nesting reveals long distance colonisation in the philopatric loggerhead sea turtle (Caretta caretta)
2018
The colonisation of new suitable habitats is crucial for species survival at evolutionary scale under changing environmental conditions. However, colonisation potential may be limited by philopatry that facilitates exploiting successful habitats across generations. We examine the mechanisms of long distance dispersal of the philopatric loggerhead sea turtle (Caretta caretta) by analysing 40 sporadic nesting events in the western Mediterranean. The analysis of a fragment of the mitochondrial DNA and 7 microsatellites of 121 samples from 18 of these nesting events revealed that these nests were colonising events associated with juveniles from distant populations feeding in nearby foraging gro…
Assessing global range expansion in a cryptic species complex: insights from the red seaweed genus Asparagopsis (Florideophyceae)
2017
The mitochondrial genetic diversity, distribution and invasive potential of multiple cryptic operational taxonomic units (OTUs) of the red invasive seaweed Asparagopsis were assessed by studying introduced Mediterranean and Hawaiian populations. Invasive behavior of each Asparagopsis OTU was inferred from phylogeographic reconstructions, past historical demographic dynamics, recent range expansion assessments and future distributional predictions obtained from demographic models. Genealogical networks resolved Asparagopsis gametophytes and tetrasporophytes into four A. taxiformis and one A. armata cryptic OTUs. Falkenbergia isolates of A. taxiformis L3 were recovered for the first time in t…
Levels of genetic differentiation and gene flow between four populations of the Scaly-naped Pigeon, Patagioenas squamosa : implications for conservat…
2021
Island-endemic columbid species are particularly vulnerable to environmental degradation, extreme climatic events, and interactions with exotic species. The situation might be even more critical in the case of exploited species, where legal hunting and poaching can severely affect population dynamics. Here we document for the first time the genetic structure of the Scaly-naped Pigeon, Patagioenas squamosa, a Caribbean-endemic columbid species of cynegetic interest, over a large part of its range. Using both mitochondrial DNA and nuclear markers (microsatellites), we investigated gene flow, genetic diversity, and genetic structure among four islands populations originating from Puerto-Rico, …
Phylogenetic evidence for hybrid origins of asexual lineages in an aphid species
2003
International audience; Understanding the mode of origin of asexuality is central to ongoing debates concerning the evolution and maintenance of sexual reproduction in eukaryotes. This is because it has profound consequences for patterns of genetic diversity and ecological adaptability of asexual lineages, hence on the outcome of competition with sexual relatives both in short and longer terms. Among the possible routes to asexuality, hybridization is a very common mechanism in animals and plants. Aphids present frequent transitions from their ancestral reproductive mode (cyclical parthenogenesis) to permanent asexuality, but the mode of origin of asexual lineages is generally not known bec…
Morphological and molecular tools in identifying the Mediterranean limpets Patella caerulea, Patella aspera and Patella rustica
2003
Allozyme electrophoresis, a partial nucleotide sequence of a mitochondrial gene for cytochrome oxidase I (COI) and discriminant analysis of shell morphometric characters were used to study the relationships among the Sicilian marine gastropods of the Patella genus. Allozyme and mtDNA markers unequivocally distinguished the species and were very useful markers in correctly classifying the different species when morphological characters overlapped each other. Several allozyme loci and many nucleotide positions were diagnostic of species. In contrast, the discriminant analysis of simple morphometric shell characters failed to adequately discriminate the species, suggesting that environmental f…
Deep divergence and evidence for translocations between Iranian and European populations of the alfalfa weevil (Coleoptera: Curculionidae) based on m…
2016
AbstractThe alfalfa weevil (Hypera postica(Gyllenhal): Coleoptera: Curculionidae) is an invasive pest of alfalfa (Medicago sativaLinnaeus; Fabaceae) in the Holarctic region. Across the wide geographic distribution of the species different local adaptions have been observed. Further, several distinct mitochondrial lineages have been discovered, which have been treated as western and Egyptian/eastern strains. However, our knowledge of the biogeography ofH. posticais largely limited to North American and Japanese populations. We sampled the species from four locations in Iran and two countries in Europe (Poland and Czech Republic) and sequenced the mitochondrial COI gene to detect patterns of …