| Abstract: | Actin in the sperm head of Talpa europaea was observed by immunofluorescence and immunoelectron microscopy. The indirect immunofluorescence technique, using both anti-actin and DNase anti-DNase methods, showed a shining fluorescent band around the sperm head in some spermatozoa, whereas in others the fluorescence was found in the postacrosomal region. Since no labeling was detected in sperms treated with NBD-phallacidin, it is likely that mature mole sperms contain G-actin but not F-actin. The results of electron microscopy indicated the deposition of the anti-actin antibodies in two places in mole spermatozoa: the postacrosomal region and the nuclear segment of the acrosome. In the first case, the actin was localized in the space between the outer surface of the postacrosomal sheath and the plasma membrane; in the second one, the actin was localized in the space between the outer acrosomal membrane and the plasma membrane. The significance of the presence of actin and its role(s) during fertilization are discussed. |
