[
1985]
Expression of the vitellogenin genes is restricted to the intestine of adult hermaphrodite C. elegans. In order to identify potential cis-acting elements involved in this developmental regualtion, we have sequenced the regions surrounding the 5' ends of five of the six members of this gene family. In addition, we have sequenced several of the promoters from the homologous genes from the related species C. briggsae. Although the various promoters are largely diverged from one another, we have discovered two potential regulatory sequences within the first 250 bp upstream of each of the genes. The first, TGTCAAT, occurs eight times as a perfect heptamer upstream of the five C. elegans genes, at least once per promoter. Allowing a 1 bp mismatch, the element is found in both orientations a total of 27 times, four to six timer per promoter. It is present preferentially at two locations: just upstream of the TATA box and, in the opposite orientation, at position -180. The second sequence, CTGATAA, is also present as a perfect heptamer in a restricted region of each promoter: near position -135. Remarkably, this sequence is also found upstream of the vitellogenin genes of vertebrates. Both sequences have been conserved in the C. briggsae promoters. We hypothesize that these two sequences are involved in the sex-, tissue-, and stage-specific expression of the vitellogenin genes.