Pattern of peptide synthesis in Drosophila cell lines and their hybrids.

Significant changes occurred in the rate of synthesis of several polypeptides in two different Drosophila cell lines following exposure to the steroid hormone, beta-ecdysone. For peptide 7/8, the synthetic rate increased by a factor of 10 in line S3 and by a factor of 1.3 in line MDR. In hormone-sensitive hybrids the rate increased by a factor of 3-4.5. For peptide 10 the synthetic rate decreased by a factor of 8 in line S3 but increased by a factor of 2 in line MDR. In hormone-sensitive hybrids the synthetic rate increased by a factor of 2-3. In hormone-insensitive cell lines no change in the rate of peptide synthesis occurred in the presence of hormone.