Molecular and General Genetics MGG

, Volume 191, Issue 2, pp 326–333

Genes which suppress position-effect variegation in Drosophila melanogaster are clustered

  • Donald A. R. Sinclair
  • Randall C. Mottus
  • Thomas A. Grigliatti
Article

DOI: 10.1007/BF00334834

Cite this article as:
Sinclair, D.A.R., Mottus, R.C. & Grigliatti, T.A. Mol Gen Genet (1983) 191: 326. doi:10.1007/BF00334834

Summary

We have isolated more than 50 dominant suppressors and 3 dominant enhancers of position effect variegation in Drosophila melanogaster. To our surprise, genetic mapping studies revealed that the Su(var) mutations are not randomly dispersed throughout the genome of this organism. Rather they fall into very discrete clusters. Moreover, all of the induced Su(var) mutations which map to a major second chromosome cluster are recessive lethal, whereas all of those which map within any of several third chromosome clusters are viable. Complementation analysis involving Su(var) mutations located within the 2L cluster suggests that several different loci occupy this site. Thus, these clusters may represent groupings of functionally related but distinct Su(var) loci.

A subset of the suppressors were examined for their effects on several different variegating rearrangements. The results suggest that the suppressing ability of the mutants is general. Interestingly, the effects of the suppressors in males appears to be highly dependent upon the presence of the Y chromosome. Finally, examination of the Su(var) mutants at different developmental temperatures indicated that at least one of them is temperature-sensitive. These findings are discussed with respect to the potential for genetic and functional dissection of loci which encolde chromosomal components.

Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • Donald A. R. Sinclair
    • 1
  • Randall C. Mottus
    • 1
  • Thomas A. Grigliatti
    • 1
  1. 1.Department of ZoologyThe University of British ColumbiaVancouverCanada