Neural cadherin in murine sperm and COCs and its participation in fertilization

VERON G; ROSSO M; MENCUCCI, MV; VEIGA F; MARIN BRIGGILER, CI; VAZQUEZ LEVIN, MÓNICA

Buenos Aires

Congreso; XVIII Jornadas Anuales Multidisciplinarias 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 fertilization site. Since gamete interaction involves adhesion events and presence of Ca2+ions, the involvement of the Ca+2-dependent adhesion protein Neural Cadherin (N-Cadherin) was studied. We previously reported the expression of N-cadherin in both human sperm and oocytes and presented evidence of its participation in gamete interaction, describing the ability of specific antibodies to impair sperm-oocyte interaction. The present study was designed to evaluate the expression of N-cadherin in murine gametes and reproductive tissues and its involvement in fertilization-related events. N-cadherin mRNA expression was determined by qRT-PCR in adult testis and epididymis, as well as in ovary, GV- and MII-oocytes, finding the highest levels in testis and MII-oocytes. Western immnoblot analysis revealed the presence of the mature135 KDa protein in gonads and gametes. By fluorescence immunocytochemistry, N-cadherin was detected in the acrosomal cap of testicular sperm and in the acrosoml region and equatorial segment of acrosome-intact non-capacitated and capacitated (FITC-PSA/anti-Ncadherin) epididymal sperm. Contrasting, Progesterone-induced acrosome-reacted sperm showed N-cadherin signal mainly localized in the equatorial segment. Immunodetection of N-cadherin was confirmed in mature cumulus cells and MII-oocytes. In sperm-oocyte interaction assays, gamete preincubation with specific N-cadherin antibodies (H-63, StaCruz & GC-4, SIGMA) resulted in decreased COCs fertilization (48.2% of control, p