INTERACTIONS BETWEEN CUT WING MUTATIONS AND MUTATIONS IN ZESTE, AND THE ENHANCER OF YELLOW AND POLYCOMB GROUP GENES OF DROSOPHILA-MELANOGASTER

The phenotypic expression of several mutations in the cut locus of Dro sophila melanogaster is modified by mutations in the zeste, e(y)2 and e(y)3 genes and in some genes of the Polycomb group. All tested sensit ive cut mutations have a partially inactivated cut wing enhancer, e(y) 3(u1), z(v77h) and Su(z)2(5) mutations enhance, while e(y)2(u1), z(Op6 ), Psc(1), Su(z)301, Su(z)302 and Scm(D1) mutations suppress the ct mu tant phenotype. The results are discussed in terms of the role of long -distance interactions and DNA compaction in transcriptional control o f the cut locus.