mRNA populations during wing development in the silkmoth Antheraea polyphemus

Pupal wing tissue of the American silkmoth Antheraea polyphemus has been used as a model system to study 20-hydroxyecdysone and juvenile hormone control of cuticle protein synthesis. Juvenile hormone does not affect either the content or rate of synthesis of RNA and protein of the wing tissue. both of which show linear increases during the first few days of hormonal treatment. Based on the fractionation of total RNA on oligo-dT columns the percent of mRNA remains the same throughout development after both hormone treatments. However, both the amount of poly-A+ RNA in the wing tissue, and its content of poly-A show considerable increases as a function of development. The products of translation of the various poly-A+ RNA populations in the cell-free wheatgerm system have been analyzed by one- and two-dimensional gel electrophoresis and fluorography. Qualitative changes occur during the first 24 h; the production of a mRNA coding for a protein of approx. 40 000 dalton is stimulated and the production of a mRNA coding for a protein of 29 000 dalton is greatly reduced. Only a few differences are observed between samples from the 2 hormone treatments. Over the next 5-15 days of development mainly quantitative changes are observed. Juvenile hormone application results in quantitative changes in specific mRNAs, but no new mRNAs unique to juvenile hormone action are observed. The data are consistent with the concept that in altering the epidermal developmental program, juvenile hormone is apparently modulating the action of 20-hydroxyecdysone.