Participation of neural cadherin in human gamete interaction

DEL POZO, M; MARIN BRIGGILER, CI; GONZALEZ ECHEVERRIA, F; RAWE, V; ALVAREZ SEDO, C; VAZQUEZ LEVIN, M

Buenos Aires

Jornada; XI Jornadas Anuales de la Sociedad Argentina de Biología; 2009

Sociedad Argentina de Biología

Introduction: Previous studies from our laboratory have described the localization of the adhesion molecule neural cadherin (N-cad) in the acrosomal region of intact human spermatozoa and in the equatorial segment of reacted cells. Objetive: To evaluate the participation of N-cad in sperm interaction with the zona pellucida (ZP) and the oolemma. Methods: The hemizona and ZP-free hamster oocyte sperm penetration assays were carried out, in which gametes were preincubated with anti N-cad antibodies directed towards different extracellular domains of the protein (clone GC-4, Sigma, domain 1; H-63, Santa Cruz Biotech., domain 3-4). Results and Discussion: Sperm preincubation with either H-63 (10 and 100 mg/ml) or GC-4 (20 and 200 mg/ml) did not affect their ability to bind to the homologous ZP in the hemizona assay (data not shown). Contrasting, preincubation of both gametes with anti N-cad antibodies led to a significant decrease (P<0.01) in the number of sperm penetrations per oocyte in comparison with controls (% inhibition for H-63 20 mg/ml: 57±12%, mean±SEM, n=3 assays; GC-4 200 mg/ml: 51±11%, n=8 assays). A similar effect was found when only oocytes were preincubated with the antibodies. N-cad was immunodetected in human and hamster oocytes. The results suggest that N-cad has a role in gamete adhesion/fusion but would not participate in sperm-ZP interaction.