Functional interactions between promoters of neighboring yellow and CG3777 genes in Drosophila melanogaster

It was shown by us previously that the transcription of the yellow gene can be affected by the promoter of the neighboring gene CG3777, which has a similar expression profile. In the present work, we continued studying the functional interactions between the promoters of the yellow and CG3777 genes in transgenic Drosophila strains. In this work, we used the failure of the yeast activator GAL4 to stimulate transcription from the promoter of the yellow gene for the case when GAL4-binding sites are localized at the 3'-end of the gene. It has been found that, if the 983-bp CG3777 gene promoter is inserted in transgenic strains in the same orientation with the yellow gene promoter, downstream from the sites of the GAL4 activator, the CG3777 promoter provides a strong stimulation of the yellow gene by the GAL4 activator. When the promoters of the yellow and CG3777 genes are inserted in opposite orientations relative to one another, no stimulation of the yellow gene by GAL4 is observed. Additional results obtained in the work demonstrate that the functional interacton between the CG3777 and yellow promoters depends on their mutual orientation and position relative to the GAL4-binding sites.