Abstract
The e(y)1/TAFII40, e(y)2 and e(y)3 genes encode general transcription factors in Drosophila melanogaster. Weak mutations in e(y)1u1, e(y)2u1 and e(y)3u1 regulate enhancer-dependent transcription of the yellow gene in bristles similarly, even if it is activated by a non-yellow specific enhancer element. At the same time, these mutations do not affect yellow expression in the body and wings. We found genetic data indicating that the e(y) proteins support the promoter/bristle enhancer interaction. Futhermore, the su(Hw) insulator properties change in the presence of e(y)1u1, e(y)2u1 and e(y)3u1 mutations. When introduced at +2490 from the transcription initiation site, the su(Hw) insulator becomes able to block interactions between the bristle enhancer and yellow promoter, not separating them from each other.
