The actin loci in the genus Drosophila: establishment of chromosomal homologies among five nearctic species of the Drosophila obscura group by in situ hybridization

Chromosoma. 2002 Nov;111(4):256-66. doi: 10.1007/s00412-002-0207-3. Epub 2002 Sep 6.

Abstract

The actin genes of five nearctic species of the Drosophila obscura group were mapped by in situ hybridization, using the 5C actin gene of D. melanogaster as a probe. In all species but D. azteca eight actin loci were observed variously dispersed over all five (A- E) chromosomal elements. In D. azteca ten actin hybridization sites were found; four of which most probably originated by duplications or by transposition events. Although the five nearctic species differ from all other Drosophila species of the D. obscura group so far studied in the number of loci as well as in the chromosomal distribution and location of the actin loci, the uniformity of the main pattern with six actin loci throughout the genus Drosophila reinforces the hypothesis that the chromosomal elements have maintained their essential identities during the course of evolution. Our findings are in accordance with the conclusion that the nearctic D. obscura species have differentiated from a common ancestor of the palearctic species and that they belong to two distinct subgroups, the pseudoobscura and the affinis subgroups.

MeSH terms

  • Actins / genetics*
  • Animals
  • Chromosome Mapping
  • Chromosomes*
  • Drosophila / classification*
  • Drosophila / genetics*
  • In Situ Hybridization / methods*
  • Phylogeny
  • Salivary Glands

Substances

  • Actins