[Suppressor mutation, interacting with the white alleles of Drosophila melanogaster]

A system of genetic instability was developed by crosses of males y2 wa4 with females C(1)DX, ywf. Mutations occurred in the second and third generations with the rate 0.7.10(-3)-1.5.10(-3). A novel gene named Suppressor of wa4--Su(wa4) was selected in this system. The Su(wa4)M1 is dominant and was localised in the position of 309 map units. Su(wa4)M1 suppressed wa, wa4, wbf, waG which had insertions of different transposable elements in different introns of the white locus. However, Su(wa4) does not interact with other w mutations. So, we suggested that Su(wa4) is trans-regulatory gene and its product involves in the expression regulation the white locus, probably, on the transcriptional level.