mRNAs of wing epidermis of the oak silkmoth Antheraea polyphemus and other silkmoths during pupal development

Abstract The mRNA populations of wing epidermal cells of the silkmoth Antheraea polyphemus during juvenile hormone induced second pupal development have been analyzed by two techniques. The analysis of the data derived from hybridization of cDNAs to the corresponding mRNAs demonstrate that the mRNAs are complex during the entire period of pupal development. Each mRNA population hybridizes to its cDNA over five orders of Rot and belong to three abundance classes. A comparison of the hybridization of two mRNAs derived from the wing epidermis at the beginning of development and at the end of pupal development with each other's cDNAs shows that only about 60% of the messages are common between the two stages. The 40% of the mRNAs that are new and abundant at the time of second pupal cuticle synthesis have been isolated as pupal specific (null) cDNAs and characterized by hybridization to various mRNAs. Quantitative analysis of the data shows that the mRNAs corresponding to these specific cDNAs are about 200 in number and appear at 4 days of pupal development. The mRNAs derived from the pupal wing epidermis of three other silkmoths can also hybridize to the polyphemus pupal specific cDNAs to varying extents demonstrating the presence of similar mRNAs in their wing epidermis at the appropriate time. The differences in the hybridization patterns seen with the various mRNA populations and the appearance of new and abundant mRNAs at 4 days of pupal development have been correlated with two dimensional gel electrophoretic patterns of the in vitro translation products from the same mRNAs. A comparison of these patterns demonstrate the appearance of several new mRNAs at the time of pupal cuticle synthesis. The translation products of these mRNAs appear to have isoelectric points and molecular weights similar to those of the major pupal cuticular polypeptides. The translation products of the mRNAs derived from the pupal wing epidermis of other silkmoths also yield 2-D gel patterns quite similar to that of polyphemus silkmoth. The hybridization data and the 2-D gel patterns of the translation products of mRNAs isolated from the abdominal and pupal wing epidermis derived from primary pupae are indistinguishable from those of mRNAs derived from secondary pupal wing epidermis.