Earlier, mutations at six loci designated enhancers of yellow (e(y)1-6) were obtained in the system of prolonged instability, where transpositions of Stalker mobile element occur. These mutations decrease pigmentation of the cuticle in a number of alleles. In the present work, genetic analysis of the mechanism of action of e(y)1u1, e(y)3u1 and newly described e(y)7u1 mutations on the yellow locus expression was conducted. The data are obtained proving that the enhancers of yellow 1 and 3 control transcription of the yellow locus. At the same time, the interaction of here described gene e(y)7 with the yellow gene is likely to occur at the level of protein products.