Positive selection near an inversion breakpoint on the neo-X chromosome of Drosophila americana.

ABSTRACT: Unique features of heteromorphic sex chromosomes are produced as a consequence of sex-linked transmission. Alternative models concerning the evolution of sex chromosomes can be classified in terms of genetic drift or positive selection being the primary mechanism of divergence between this chromosomal pair. This study examines early changes on a newly acquired chromosomal arm of the X in Drosophila americana, which was derived from a centromeric fusion between the ancestral X and previously autosomal chromosome 4 (element B). Breakpoints of a chromosomal inversion In(4)a, which is restricted to the neo-X, are identified and used to guide a sequence analysis along chromosome 4. Loci flanking the distal breakpoint exhibit patterns of sequence diversity consistent with neutral evolution, yet

SUBMITTER: Evans AL 

PROVIDER: S-EPMC2147947 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature