Patterns of sequence variability and divergence at the diminutive gene region of Drosophila melanogaster: complex patterns suggest an ancestral selective sweep. Journal Article uri icon

Overview

abstract

  • To identify putatively swept regions of the Drosophila melanogaster genome, we performed a microsatellite screen spanning a 260-kb region of the X chromosome in populations from Zimbabwe, Ecuador, the United States, and China. Among the regions identified by this screen as showing a complex pattern of reduced heterozygosity and a skewed frequency spectrum was the gene diminutive (dm). To investigate the microsatellite findings, nucleotide sequence polymorphism data were generated in populations from both China and Zimbabwe spanning a 25-kb region and encompassing dm. Analysis of the sequence data reveals strongly reduced nucleotide variation across the entire gene region in both the non-African and the African populations, an extended haplotype pattern, and structured linkage disequilibrium, as well as a rejection of neutrality in favor of selection using a composite likelihood-ratio test. Additionally, unusual patterns of synonymous site evolution were observed at the second exon of this locus. On the basis of simulation studies as well as recently proposed methods for distinguishing between selection and nonequilibrium demography, we find that this "footprint" is best explained by a selective sweep in the ancestral population, the signal of which has been somewhat blurred via founder effects in the non-African samples.

publication date

  • October 1, 2007

Full Author List

  • Jensen JD; Bauer DuMont VL; Ashmore AB; Gutierrez A; Aquadro CF

Other Profiles

Additional Document Info

start page

  • 1071

end page

  • 1085

volume

  • 177

issue

  • 2