Genetic analysis of the hormonally regulated yolk polypeptide genes in D. melanogaster.

To initiate a genetic study of the hormonal regulation of genes coding for the three vitellogenins or yolk polypeptide precursors (YPs) in Drosophila, we have isolated from wild flies genetic variants which alter the mobility in SDS-PAGE of each YP independently. These variants are expressed codominantly and they are sex-linked: Yp1 and Yp2 map to region 8E to 9B1 (locus 30) and Yp3 is in 12A6-7 to 12D3 (locus 44). The amount of each YP synthesized and secreted into the hemolymph is related to the dosage of the above regions, suggesting that the structural genes are in those intervals. These experiments raise the question of the functional role of the proximity of Yp1 and Yp2 and provide a mechanism for a search for mutations altering the hormonally regulated function of these three genes.