Tracking the origin of the American colonization by Drosophila subobscura: genetic comparison between Eastern and Western Mediterranean populations

摘要: Several pieces of evidence indicate a Mediterranean origin the colonization America by Drosophila subobscura. To ascertain whether was from Eastern or Western region, samples Barcelona (Spain) and Mt Parnes (Greece) were collected O chromosomal inversion polymorphism lethal genes analysed. The frequencies chromosomes 0.244 ± 0.039 in 0.336 0.043 Parnes, consistent with expectations for large populations located central area species distribution. Lethal seem to be distributed at random along chromosome both populations. intra-populational allelism 0.016 0.007 0.012 0.005 respectively. Thus, estimates effective population size high (between 6964 13 004 11 874 26 828 Parnes). cases observed only between individual genes, but some concatenated clusters detected. This pattern can explained synthetic lethality, hybrid dysgenesis, induction recurrent mutations different factors an effect microdifferentiation subpopulations. In populations, reduction fitness heterozygotes has been Furthermore, migration coefficient 0.0085 0.0120 Barcelona, 0.0057 0.0087 Parnes) confirm existence gene flow Palearctic D. Our results are subobscura, inconclusive regard identification which these colonizers came.