Variation in Sperm Head Morphology in the Australian Rodent Notomys alexis

Abstract

Scanning electron microscopy of the sperm head of the hopping-mouse indicates considerable variability in shape, much of which is probably due to the fragility of the acrosome. However, fluorescence microscopy of the sperm after staining with 4'-6-diamidino-2-phenylindole (DAPI) indicates some nuclear variability as well. Such polymorphism in sperm head morphology is unusual in mammals; its functional significance remains to be determined.