Abstract
We cloned and characterized the yellow locus of Drosophila melanogaster. We also studied its transcription pattern in the suppressible allele y2, which is caused by the insertion of the transposable element gypsy, and the effect of mutations at the unlinked suppressor of Hairy-wing locus on the transcription of yellow RNAs. The gypsy element is transcribed in a temporal fashion that correlates with the pattern of expression of the yellow locus. We propose that the mutational effect of the gypsy element is due to developmentally specific transcriptional interference on yellow transcription. Mutations at the su(Hw) locus reverse this effect by altering the quantitative expression of gypsy.