<i>DESATURASE‐2</i>, ENVIRONMENTAL ADAPTATION, AND SEXUAL ISOLATION IN<i>DROSOPHILA MELANOGASTER</i>

Abstract

In a previous paper In their study, Greenberg et al. used targeted gene replacement to construct lines having different alleles of the desaturase-2 (desat2) locus-a gene involved in synthesis of cuticular hydrocarbons. They found that different alleles had different effects on flies' responses to cold and starvation stress: carriers of the African and Caribbean allele (ds2 Z ) consistently had less cold resistance and greater starvation resistance than carriers of the Cosmopolitan allele (ds2 M ). Because there was earlier evidence for sexual isolation between carriers of different desat2 alleles (African females homozygous for ds2 Z discriminate against non-African males homozygous for ds2 M ; Fang et al. 2002), possibly because different cuticular hydrocarbons act as mating cues,