Search results for "RILIS"
showing 10 items of 33 documents
Phylogeographic patterns in Drosophila montana
2006
The Drosophila virilis species group offers valuable opportunities for studying the roles of chromosomal re-arrangements and mating signals in speciation. The 13 species are divided into two subgroups, the montana and virilis 'phylads'. There is greater differentiation among species within the montana phylad in both karyotype and acoustic signals than exists among members of the virilis phylad. Drosophila montana is a divergent species which is included in the montana phylad. Here, we analyse the phylogeography of D. montana to provide a framework for understanding divergence of acoustic signals among populations. We analysed mitochondrial sequences corresponding to the cytochrome oxidase I…
Evolution of gypsy Endogenous Retrovirus in the Drosophila obscura Species Group
2000
The Ty3/gypsy family of retroelements is closely related to retroviruses, and some of their members have an open reading frame resembling the retroviral gene env. Sequences homologous to the gypsy element from Drosophila melanogaster are widely distributed among Drosophila species. In this work, we report a phylogenetic study based mainly on the analysis of the 5' region of the env gene from several species of the obscura group, and also from sequences already reported of D. melanogaster, Drosophila virilis, and Drosophila hydei. Our results indicate that the gypsy elements from species of the obscura group constitute a monophyletic group which has strongly diverged from the prototypic D. m…
Microsatellite-based species identification method for Drosophila virilis group species
2007
Species of the D. virilis group are widely used in evolutionary research, but the individuals of different species are difficult to distinguish from each other morphologically. We constructed a fast and easy microsatellite-based identification method for the species of the group occurring sympatrically in northern Europe. The neighbor joining tree based on 14 microsatellite loci also gave a good resolution of the species divergence pattern in the whole group.
Sequence, molecular organization and products of the Drosophila virilis homologs of the D. melanogaster nested genes lethal(2)tumorous imaginal discs…
1997
Abstract In this study, we describe the isolation of the Drosophila virilis (Dvir) 6201-bp genomic fragment homologous to a 7047-bp genomic region of D. melanogaster (Dmel) that harbors the nested genes lethal(2)tumorous imaginal discs (l(2)tid), lethal(2)neighbour of tid (l(2)not) and lethal(2)relative of tid (l(2)rot). The isolated fragment, which maps at the cytogenetic position 50A5 on chromosome 5, carries the Dvir homologs of the Dmel genes l(2)tid and l(2)not. In both cases, the interspecific comparison of the determined sequences reveals a high homology regarding the protein coding regions and a high degree of evolutionary divergence concerning the intronic parts of the genes. In th…
On-line implementation and first operation of the Laser Ion Source and Trap at ISOLDE/CERN
2015
13 pags.; 12 figs.; 2 tab.; Open Access funded by CERN
Cuticular hydrocarbons of Drosophila montana: geographic variation, sexual dimorphism and potential roles as pheromones.
2014
Abstract Sexual selection within populations can play an important role in speciation when divergence in mating signals and their corresponding preferences occur along different coevolutionary trajectories in different populations. In insects, one potential target of sexual selection is the blend of cuticular hydrocarbons (CHCs), which often show intra- and interspecific variation, sexual dimorphism and may act as pheromones. In Drosophila montana, a cold-adapted, circumboreal member of the Drosophila virilis species group, flies from different populations have been found to show significant premating isolation as well as variation in male mating signal (song) and female preference. While t…
Sequence variation in couch potato and its effects on life-history traits in a northern malt fly, Drosophila montana
2011
Abstract Couch potato ( cpo ) has previously been connected to reproductive diapause in several insect species including Drosophila melanogaster , where it has been suggested to provide a link between the insulin signalling pathway and the hormonal control of diapause. In the first part of the study we sequenced nearly 3.6 kb of this gene in a northern Drosophila species ( Drosophila montana ) with a robust photoperiodically determined diapause and found several types of polymorphisms along the sequenced area. We also found variation among five Drosophila virilis group species in the length of the 5th exon of cpo and in the site of the stop codon at the end of this exon. The second part of …
A microsatellite linkage map forDrosophila montanashows large variation in recombination rates, and a courtship song trait maps to an area of low rec…
2009
Current advances in genetic analysis are opening up our knowledge of the genetics of species differences, but challenges remain, particularly for out-bred natural populations. We constructed a microsatellite-based linkage map for two out-bred lines of Drosophila montana derived from divergent populations by taking advantage of the Drosophila virilis genome and available cytological maps of both species. Although the placement of markers was quite consistent with cytological predictions, the map indicated large heterogeneity in recombination rates along chromosomes. We also performed a quantitative trait locus (QTL) analysis on a courtship song character (carrier frequency), which differs be…
Signals of demographic expansion in Drosophila virilis
2008
Background. The pattern of genetic variation within and among populations of a species is strongly affected by its phylogeographic history. Analyses based on putatively neutral markers provide data from which past events, such as population expansions and colonizations, can be inferred. Drosophila virilis is a cosmopolitan species belonging to the virilis group, where divergence times between different phylads go back to the early Miocene. We analysed mitochondrial DNA sequence variation among 35 Drosophila virilis strains covering the species' range in order to detect demographic events that could be used to understand the present characteristics of the species, as well as its differences …
« Pour mes trente ans je me fais stériliser. » Stérilisées et sans enfant : une utilisation déviante de la contraception ?
2018
International audience; Cet article se focalise sur les femmes sans enfant et présente une utilisation singulière de la contraception : non pas pour « avoir un enfant comme on veut, quand on veut », mais pour choisir de ne jamais en avoir. L’enquête ethnographique se penche sur l’appréhension de cette pratique tant par les médecins que par les femmes stérilisées ou en voie de l’être. Demande déviante pour les médecins qui régulent fortement l’accès à cette méthode, cet acte est pourtant approprié comme un élément constitutif de la « culture childfree ». Le sujet invite à se pencher sur le discours de ces femmes, qui, s’il est « déviant » n’en est pas moins révélateur d’une générale aspirati…