IDENTIFICATION OF SPECTRIN AND CALMODULIN IN RABBIT SPERMIOGENESIS AND SPERMATOZOA

Actin was localized in the four subacrosomal bulges (Camatini et al., Eur. J. Cell Biol. 45:276–281, 1987), which characterize the sperm head of rabbit spermatozoa (Phillips, J. Ultrastruct. Res. 38:591–604, 1972), and in the postacrosomal region (Welch and O'Rand, Dev. Biol. 109:411–417, 1985; Camatini et al., Eur. J. Cell Biol. 45:276–281, 1987). Specific antibodies and indirect immunogold labelling on testis Lowicryl K4M sections and spermatozoa cryosections were used to study the distribution of calmodulin and a spectrin‐like protein. This protein was also present close to the shaping membranes of the head. The results presented suggest a membrane‐cytoskeletal role of actin, spectrin, and calmodulin. Copyright © 1991 Wiley‐Liss, Inc.