The sperm head of the plains mouse,Pseudomys australis: Ultrastructure and effects of chemical treatments

The ultrastructure of the sperm head of the plains mouse, Pseudomys australis, and the effects of chemical treatments on the sperm head components has been investigated to determine the nature of the material in the hooks on the apical margine of the sperm head. Ultrastructural studies indicated that the dorsal hook contained nuclear, subacrosomal, and acrosomal material, whereas the two ventral hooks were largely composed of an extention of the subacrosomal material with two thin acrosomal projections at their base. Acrosomal material was dispersed by mild detergent treatment, where as the bulk of the material in the ventral hooks were generally found to be similar to the subacrosomal material in the dorsal hook in their resistance to the various chemical treatments. Treatment of sperm with NaOH or guanidine-hydrochloride and DTT revealed two layers of material in the ventral hooks.