Serine protease activity, BSp66, is present in hamster sperm and is involved in sperm-zona interaction

ANDREINA CESARI; KATUNAR, M. R.; MONCLUS, M. A.; VINCENTI, A.; ROSAS, J. C.; FORNÉS, M. W.

Reproduction

Año: 2005 vol. 129 p. 291 - 298

1470-1626

BSp66 is a new serine protease previously characterized in bovine spermatozoa. Like other proteases, it may be present in sperm from other mammalian species different from bovine playing a role in the fertilization process. In this study, we looked for BSp66 in hamster spermatozoa using heterologous antibodies against bovine BSp66. An immunoreactive protein was detected by Western blotting in mature  and immature sperm. The detected protein had two isoforms similar to the ones reported in bovine sperm. Furthermore, indirect immune detection by fluorescence and electron microscopy assays, showed BSp66 signal at the acrosomal region similar to bovine sperm. As it was determined in bovine sperm, the acrosomal reaction displays  the antigen  within the acrosomal content. When live hamster sperm was incubated with polyclonal antibody against bovine BSp66 a decrease in the number of sperm bound to zona pellucida in homologous IVF and an impairment of head-head agglutination, were observed. These results suggest that a protease homologous to bovine BSp66 is present in golden hamster spermatozoa, with a conserved molecular mass and cellular location. Moreover, hamster BSp66 is probably involved in zona pellucida recognition.