Temporal deposition and spatial distribution of cytoskeletal proteins in the sperm head of an Australian rodent.

The Australian murine rodent, the plains mouse (Pseudomys australis), possesses a highly complex sperm head, in which there are, in addition to an apical hook, two ventral processes that extend from its upper concave surface. The present study set out to determine the temporal deposition and distribution of the proteins within these structures during late spermiogenesis by light and electron microscopy using various antibodies to bull and laboratory rat sperm-head cytoskeletal proteins. The findings show that there are two phases of protein deposition.

Protein composition of the ventral processes on the sperm head of Australian hydromyine rodents.

The sperm head of the plains rat, an Australian hydromyine rodent, is highly complex in structure and contains, in addition to an apical hook, two large ventral processes (VPs) that extend from its upper concave surface and that are largely composed of a huge extension of the sperm head cytoskeleton surrounded by postacrosomal dense lamina. In this study we have attempted to determine their protein composition. For this, the VPs were isolated, the proteins within them separated by SDS-PAGE, and the resultant polypeptide bands Western blotted and probed with antibodies against laboratory rat perforatorial and bull perinuclear theca sperm proteins.