Neural Cadherin in Murine Sperm and COCs and its Participation in Fertilization

VERÓN, GUSTAVO LUIS; MENCUCCI, MARÍA VICTORIA; MARÍN-BRIGGILER, CLARA ISABEL; ROSSO, MARINA; VEIGA, MARÍA FLORENCIA; VAZQUEZ-LEVIN, MÓNICA HEBE

CABA

Congreso; XVIII Congreso de la Sociedad Argentina de Biología; 2016

Sociedad Argentina de Biología

Mammalian fertilization involves an organized sequence of molecular events throughout the spermatozoan journey to the fertilizationsite. Since gamete interaction implicates adhesion events and presence of Ca2+ions, the involvement of the Ca+2-dependent adhesionprotein Neural Cadherin (N-Cadherin) was studied. We previously reported the expression of N-cadherin in both human sperm andoocytes and showed evidence of its participation in fertilization, describing the ability of specific antibodies to impair gamete interaction.The present study was designed to evaluate the expression of N-cadherin in murine gametes and reproductive tissues and its involvementin fertilization-related events. N-cadherin mRNA expression was determined by qRT-PCR in adult testis and epididymis, as well as inovary, GV- and MII-oocytes, finding the highest levels in testis and MII-oocytes. Western immunoblot analysis revealed the presence ofthe 135 KDa mature protein in gonads and gametes. By fluorescence immunocytochemistry, N-cadherin was detected in the acrosomalcap of testicular sperm and in the acrosomal region and equatorial segment of acrosome-intact non-capacitated and capacitated (FITCPSA/anti-Ncadherin) epididymal sperm. Contrastingly, Progesterone-induced acrosome-reacted sperm showed N-cadherin signal mainlylocalized in the equatorial segment. Immunodetection of N-cadherin was confirmed in mature cumulus cells and MII-oocytes. In spermoocyte interaction assays, gamete preincubation with specific N-cadherin antibodies (H-63, StaCruz & GC-4, SIGMA) resulted indecreased COCs fertilization (48.2% of control, p