Cytogenetic analysis of the echinoid (ed), dumpy (dp) and clot (cl) region in Drosophila melanogaster

Abstract

The chromosomal region surrounding the ed, dp and cl genes has been studied cytogenetically (24–26 on 2L chromosome). It contains three Minutes and a haplo-sterile function. For isolation of deficiencies and mutations these haplo-insufficient functions were covered by an insertional translocation of 24D4-25F2 into the X chromosome, or by tandem duplications. 112 lethal and visible mutations induced by EMS and X-rays have been localized by deficiency mapping to 20 subregions. They specify 42 loci in a 48 band interval consistent with the notion that most of the bands encode a single lethal function. The dp, DTS, tkv and suppressor/enhancer loci for position-effect variegation were studied in detail. A dominant suppressor function was localized within the structural part of the dp complex. New non-conditional lethals have been isolated for the DTS locus. Complementation analysis with the previously identified dominant heat-sensitive alleles places the site for heat sensitivity in the middle of the locus. Two haplo-abnormal enhancers of position-effect variegation were localized in the region 25F2–26A1. A triplo-abnormal suppressor function maps to 26B2–5; 26B9. The dose-dependent functions of these loci were studied by the use of deficiencies and duplications. © 1988, Cambridge University Press. All rights reserved.