Abstract
Capacitated cynomolgus macaque sperm have a surface hyaluronidase (PH- 20) that is evenly distributed over the entire head and can be visualized at the ultrastructural level using a secondary antibody labeled with colloidal gold. Exposure of sperm to mono-specific, bivalent polyclonal antibodies to PH-20 causes a rapid clustering of PH-20. The predominant morphological consequence of PH-20 redistribution is its aggregation along the lateral edge of the sperm head. Monovalent Fab fragments of the anti-PH-20 antibody bound to the sperm head but did not induce a change in PH-20 distribution. PH-20 aggregation was observed in almost all sperm following treatment with the polyclonal antibody, but only about 20% of the sperm had morphological acrosome reactions, regardless of the time of exposure or the concentration of antibody. There was morphological evidence of swelling of the acrosomal matrix in over 50% of the sperm following exposure to anti-PH-20 antibodies. Anti-PH-20 Fab fragments did not induce the acrosome reaction or acrosomal matrix swelling. Sperm bound to macaque zona pellucida also showed aggregation of the PH-20 protein as soon as 30 sec after sperm-zona interaction. This aggregation was not observed when macaque sperm were bound to hamster zona pellucida. When macaque sperm were surface-labeled with biotin and then incubated with anti-PH-20 antibodies or macaque zona pellucida, there was no evidence of a global surface protein rearrangement, although PH-20 protein was aggregated on the surface of the same sperm cells. An increase in levels of internal sperm Ca++ was measured in association with the antibody-induced PH-20 aggregation. Fab fragments did not increase Ca++ levels, but when they were crosslinked with anti-Fab antibody there was a significant Ca++ increase and induction of acrosome reactions. Anti- PH-20 Fab fragments did not block macaque sperm binding to macaque zona pellucida or the zona-induced acrosome reaction. We conclude that PH-20 on the sperm surface is involved in sperm-zona pellucida interaction and the zona-induced acrosome reaction.
Original language | English (US) |
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Pages (from-to) | 207-220 |
Number of pages | 14 |
Journal | Molecular Reproduction and Development |
Volume | 50 |
Issue number | 2 |
DOIs | |
State | Published - Jun 1998 |
Keywords
- Acrosome reaction
- Macaque sperm
- PH-20
- Zona pellucida
ASJC Scopus subject areas
- Genetics
- Developmental Biology
- Cell Biology