Printed in Great Britain Isolation and in vitro translation ol a mammalian protamine mRNA

mRNA was isolated from sexually mature rat, rabbit, and bovine testes. Poly(A+) and (A-) RNAs were prepared and hybridized to a rainbow-trout protamine probe. The bovine (A+) fraction showed significant hybridization compared to the other species and these related sequences were also found in total bovine DNA. Bovine mRNA programmed the in vitro synthesis of a basic protein that possessed protamine-like properties. The mRNA was fractionated by agarose-gel electrophoresis and the f r ac t i ons hybridized to the trout protamine probe. A significant hybridization signal was observed corresponding to a mRNA of approximately 400 n u c l e o t i d e s in length which coded for the protamine-like protein . The data support the view that we have i so la ted a mammal ian (bovine) protamine mRNA.