Characterization of actin isoforms in ejaculated boar spermatozoa.

Actin was localized in boar ejaculated spermatozoa by using specific antisera against cytoplasmic isoforms of actin [Otey et al., J Cell Biol, 102:1726-1737, 1986; Skalli et al., J Cell Biol, 103:2787-2796, 1986; Miller et al., Biochemistry, 26:6064-6070, 1987]. Indirect immunofluorescence and immunoelectron microscopy showed that gamma and beta actins were codistributed in the acrosomal and postacrosomal regions. Sperm actin was also identified on two-dimensional gel as two spots in the isoelectric point and molecular weight corresponding to beta and gamma actins. Coelectrophoresis of sperm actin and chicken gizzard actin and immunoblots stained with the specific antibodies confirmed the presence of these two isoforms of actin.