Intron presence-absence polymorphism in Drosophila driven by positive Darwinian selection.

ABSTRACT: Comparisons of intron-exon structures between homologous genes in different eukaryotic species have revealed substantial variation in the number of introns. These observations imply that, in each case, an intron presence-absence polymorphism must have existed in the past. Such a polymorphism, created by a recent intron-loss mutation, is reported here in a eukaryotic organism. This gene structure, detected in the jingwei (jgw) gene, segregates at high frequency (77%) in natural populations of Drosophila teissieri and is associated with a marked change in mRNA levels. Furthermore, the intron loss does not result from a mRNA-mediated mechanism as is usually proposed, but from a partial deletion at the DNA level that also results in the addition of four new amino acids to the JGW protein. Popu

SUBMITTER: Llopart A 

PROVIDER: S-EPMC123031 | biostudies-literature | 2002 Jun

REPOSITORIES: biostudies-literature