Evolution of chorion structural genes and regulatory mechanisms in two wild silkmoths: a preliminary analysis.

We report a preliminary analysis of structural and regulatory evolution of the A and B chorion gene families in two wild silkmoths, Antheraea pernyi and Antheraea polyphemus. Homospecific and heterospecific dot hybridizations were performed between previously characterized A. polyphemus complementary DNA clones and total or stage-specific follicular mRNAs from the two species. The hybridization patterns indicated substantial interspecies changes in the abundance of corresponding mRNA sequences (heteroposic evolution) without substantial changes in their developmental specificities (heterochronic evolution). In addition, the proteins encoded in the two species by corresponding mRNAs were determined by hybrid-selected translation followed by electrophoretic analysis. The results suggested that the proteins evolve in size, presumably through internal deletions and duplications.