IDENTIFICATION OF MUTATIONS IN 3 GENES THAT INTERACT WITH ZESTE IN THE CONTROL OF WHITE GENE-EXPRESSION IN DROSOPHILA-MELANOGASTER

Three previously described genes, enhancer of yellow, 1, 2 and 3, are shown to cooperate with the zeste gene in the control of white gene ex pression. The mutations e(y)1(u1), e(y)3(u1), and to a lesser extent e (y)2(u1), enhance the effect of the zeste null allele Z(v77h). Differe nt combinations of e(y)1(u1), e(y)2(u1) and e(y)3(u1) mutations with s everal other z alleles also enhance the white mutant phenotype, but on ly to levels characteristic of white alleles containing a deletion of the upstream eye enhancer. Loss of zeste protein binding sites from th e white locus does not eliminate the effect of e(y)1(u1) and e(y)3(u1) mutations, suggesting that the products of these genes interact with some other nucleotide sequences. Combinations of either e(y)1(u1) or e (y)2(u1) mutations with e(y)3(u1) are lethal. The products of these th ree genes may represent, together with zeste, a group of proteins invo lved in the organization of long-distance interactions between DNA seq uences.