INTERACTION BETWEEN GENES MOS AND MWH EXP RESSED IN SOMATIC-CELLS OF DROSOPHILA-MELANOGASTER

Gene Mosaic (Mos) of chromosome 3 of Drosophila melanogaster was locat ed by means of dominant markers Ly, Sb, and Dr. This gene was shown to be located between Ly and Sb in. the centromeric region (45 - 50 map units). An analysis of interaction between Mos and mwh genes in cis an d trans-heterozygotes showed a significant effect of the Mos gene on m utability (recombinogenesis) of chromosome mwh in somatic cells. In th e cis heterozygote mwh Mos/++, the frequency of small mutant clones on wings of flies increased. In mwh/Mos heterozygotes, the Mos gene caus ed a significant reduction of dorsocentral and scutellar bristles (78% in mwh/Mos, 85% in mwh +/+ Mos, and 98% in mwh Mos/mwh+).