Vitellogenin in Drosophila melanogaster: a comparison of the YPI and YPII genes and their transcription products.

Clones of genes coding for two of the yolk protein precursors from Drosophila melanogaster, YPI and YPII have been isolated. A single small intron was located in the YPII coding region at about the same position as it is found in YPI (6). The entire intergenic spacer region and most of the exon I from the YPII gene have been sequenced. The "capping" sites for both mRNAs have been determined using the S1 protection and cDNA synthesis methods. Comparison of the sequences which might be involved in transcriptional or translational control of these genes reveals for YPII a Hogness Goldberg box but no indication for a conserved sequence around-70-80 (CAT box). In contrast to YPI it resembles no significant homology to the 3' end of 18S rRNA. The first 60 amino acids of exon I from both genes share little homology except for the hydrophobic amino acids which should be involved in protein secretion.