Molecular variation at the In(2L)t proximal breakpoint site in natural populations of Drosophila melanogaster and D. simulans

Peter Andolfatto, Martin Kreitman

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

A previous study of nucleotide polymorphism in a Costa Rican population of Drosophila melanogaster found evidence for a nonneutral deficiency in the number of haplotypes near the proximal breakpoint of In(2L)t, a common inversion polymorphism in this species. Another striking feature of the data was a window of unusually high nucleotide diversity spanning the breakpoint site. To distinguish between selective and neutral demographic explanations for the observed patterns in the data, we sample alleles from three additional populations of D. melanogaster and one population of D. simulans. We find that the strength of associations among sites found at the breakpoint varies between populations of D. melanogaster. In D. simulans, analysis of the homologous region reveals unusually elevated levels of nucleotide polymorphism spanning the breakpoint site. As with American populations of D. melanogaster, our D. simulans sample shows a marked reduction in the number of haplotypes but not in nucleotide diversity. Haplotype tests reveal a significant deficiency in the number of haplotypes relative to the neutral expectation in the D. simulans sample and some populations of D. melanogaster. At the breakpoint site, the level of divergence between haplotype classes is comparable to interspecific divergence. The observation of interspecific polymorphisms that differentiate major haplotype classes in both species suggests that haplotype classes at this locus are considerably old. When considered in the context of other studies on patterns of variation within and between populations of D. melanogaster and D. simulans, our data appear more consistent with the operation of selection than with simple demographic explanations.

Original languageEnglish (US)
Pages (from-to)1681-1691
Number of pages11
JournalGenetics
Volume154
Issue number4
StatePublished - Apr 1 2000

All Science Journal Classification (ASJC) codes

  • Genetics

Fingerprint Dive into the research topics of 'Molecular variation at the In(2L)t proximal breakpoint site in natural populations of Drosophila melanogaster and D. simulans'. Together they form a unique fingerprint.

  • Cite this