Reiteration frequency of the protamine genes in rainbow trout (Salmo gairdnerii).

Protamine mRNA was isolated in a very pure form from trout testis and used as a template for the synthesis of a complementary DNA of high specific activity. The cDNA represented a full copy of the mRNA template and was used in hybridization reactions with purified trout DNA to determine the number of genes for protamines in trout testis. Our results indicate that there are less than four genes for each protamine polypeptide per the content of DNA in the male gamete and that the control of protamine synthesis in trout testis cells does not involve specific amplification of the protamine genes.