The Movement of Golden Hamster Spermatozoa Before and After Capacitation

Epididymal spermatozoa of the golden hamster can be capacitated in vitro in the presence of oviduct fluid from the oestrous female hamster (Yanagimachi & Chang, 1964; Yanagimachi, 1966; Barros & Austin, 1967), follicular fluid from mature ovarian follicles of the hamster (Barros & Austin, 1967; Yanagimachi, 1969a), detoxified bovine follicular fluid (Gwatkin & Andersen, 1969; Yanagimachi, 1969b), and detoxified blood sera of the hamster and some other species (Yanagimachi, 1970). When incubated in media containing these biological fluids, the spermatozoa agglutinate head to head within ½ hr. About 2½ to 3 hr later, agglutinated spermatozoa disperse spontaneously and free spermatozoa show an extraordinarily active movement. In the majority (sometimes, 100%) of these spermatozoa, the acrosomal reaction is in progress or has been completed and the spermatozoa are ready to penetrate the