Evidence that pupal and adult cuticular proteins are coded by different genes in the silkmoth Antheraea polyphemus

Abstract

The poly A + mRNAs present in the wing epidermis of the silkmoth Antheraea polyphemus during the period of synthesis of juvenile hormone-induced second pupal cuticle and adult cuticle were analysed by cDNA-mRNA hybridizations. The hybridization data indicate 60% similarity and 40% differences. The cDNAs unique to each type of cuticle (null cDNAs) were isolated and were shown to belong to the moderately abundant class. The number of mRNAs unique to each stage is calculated to be about 400. Analysis of the total mRNAs by translation in in vitro cell free systems indicate the presence of mRNAs unique to each type of cuticle which yield products with different isoelectric points and molecular weights. Similar differences were observed by comparing the cuticular polypeptides in the two kinds of cuticle using two dimensional electrophoresis. The results from the three different approaches provide evidence which supports the hypothesis that the pupal and adult cuticular proteins are coded by different messages and hence probably different genes.