Effects of ram sperm acrosin on the investments of sheep, pig, mouse and gerbil eggs.

The effects of various concentrations of highly purified preparations of ram sperm acrosin were tested in a balanced medium on the cumulus oophorus, corona radiata and zona pellucida of sheep, pig, mouse and gerbil eggs. The enzyme had a variety of effects depending upon the species of egg. These effects ranged from complete removal of all the investments from the mouse egg to a failure to remove any of the investments from the sheep egg. The in-vitro autoactivation of ram sperm proacrosin to acrosin was unmodified in the presence of various fluids from the sheep reproductive tract. It is concluded that any role for soluble ram acrosin in sperm penetration of the sheep zona pellucida is likely to be of a synergistic nature.