DNA variation at the rp49 gene region of Drosophila simulans: evolutionary inferences from an unusual haplotype structure.
An approximately 1.3-kb region including the rp49 gene plus its 5' and 3' flanking regions was sequenced in 24 lines of Drosophila simulans (10 from Spain and 14 from Mozambique). Fifty-four nucleotide and 8 length polymorphisms were detected. All nucleotide polymorphisms were silent: 52 in noncoding regions and 2 at synonymous sites in the coding region. Estimated silent nucleotide diversity was similar in both populations (pi = 0.016, for the total sample). Nucleotide variation revealed an unusual haplotype structure showing a subset of 11 sequences with a single polymorphism. This haplotype was present at intermediate frequencies in both the European and the African samples. The presence of such a major haplotype in a highly recombining region is incompatible with the neutral equilibrium model. This haplotype structure in both a derived and a putatively ancestral population can be most parsimoniously explained by positive selection. As the rate of recombination in the rp49 region is high, the target of selection should be close to or within the region studied.
Rozas
J
J
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, 08071 Barcelona, Spain. julio@bio.ub.es
Gullaud
M
M
Blandin
G
G
Aguadé
M
M
D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000235:genetics*; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D019143:Evolution, Molecular; D014644:Genetic Variation; D006239:Haplotypes; D019476:Insect Proteins / Q000235:genetics*; D015810:Linkage Disequilibrium; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic; D012269:Ribosomal Proteins; D012689:Sequence Homology, Nucleic Acid
D029721:Drosophila Proteins; D019476:Insect Proteins; D012269:Ribosomal Proteins; C107533:RpL32 protein, Drosophila; D004247:DNA