title: Population structure among African and derived populations of Drosophila simulans: evidence for ancient subdivision and recent admixture.
abstract: Previous studies based on allozyme variation have found little evidence for genetic differentiation in Drosophila simulans. On the basis of DNA sequence variation at two nuclear loci in four African populations of D. simulans, we show that there is significant structure to D. simulans populations within Africa. Variation at one of the loci, vermilion, appears to be neutral and supports an eastern African origin for European and American populations. Samples from the West Indies, Europe, and North America had a nucleotide diversity lower than that of African populations at vermilion and show nonequilibrium haplotype distributions at both vermilion and G6pd, consistent with a hypothesis of recent bottleneck and possibly also admixture in the history of these populations. Directional selection, previously documented at G6pd, appears to have occurred within the coalescence time of the species, obscuring deep population history.
authors.affiliation: Laboratoire d'Ecologie-EPHE, Université Pierre-et-Marie Curie, 75252 Paris Cedex 05, France. mhamblin@genetics.uchicago.edu
authors.forename: M T
authors.initials: MT
authors.lastname: Hamblin
authors.forename: M
authors.initials: M
authors.lastname: Veuille
mesh_terms: D000349:Africa; D000818:Animals; D001483:Base Sequence; D004330:Drosophila / Q000201:enzymology / Q000235:genetics*; D029721:Drosophila Proteins; D005060:Europe; D005136:Eye Proteins; D005787:Gene Frequency; D017344:Genes, Insect / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D019476:Insect Proteins / Q000235:genetics; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009656:North America; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D012730:Sex Chromosomes / Q000235:genetics; D014366:Tryptophan Oxygenase; D014900:West Indies
chemical_list: D029721:Drosophila Proteins; D005136:Eye Proteins; D019476:Insect Proteins; D005954:Glucosephosphate Dehydrogenase; D014366:Tryptophan Oxygenase; C121974:v protein, Drosophila