CONICET | Buscador de Institutos y Recursos Humanos

Dysadherin (Dys) is a transmembrane glycoprotein identified in several tumoral tissues and some normal cells. Dys would modulate Epithelial cadherin (Ecad) and Na/K-ATPase, proteins present in spermatozoa. Objective: to characterize the presence and localization of Dys in male reproductive tissues and spermatozoa and to evaluate its co-localization with Ecad and Na/K-ATPase. Methods: Dys expression was evaluated by RT-PCR, Western Immunoblotting and immunohisto/cytochemical analyses in testis, epididymis and spermatozoa (non-capacitated/capacitated/acrosome-reacted). The sperm acrosomal status was assessed by co-staining with FITC-Pisum sativum aglutinin. Co-immunolocalization studies of Ecad and Na/K-ATPase were done. Dys expression was also studied in mouse. Results: Dys mRNA was identified in testis, epididymis (caput/corpus/cauda) and spermatozoa. While a 91 KDa Dys protein was found in testis and spermatozoa, a 50 KDa moiety was detected in epididymis. Dys was localized to the acrosomal region of spermatids. Non-capacitated and capacitated spermatozoa were immunoreactive to Dys in the acrosomal cap and flagellum; contrasting, acrosome-reacted spermatozoa lost their label in the acrosomal region. Dys co-localized with Ecad and a4 subunit of Na/K-ATPase. In mouse, Dys mRNA was expressed in testis and epididymis, and the protein was localized to the acrosomal cap and midpiece of caput/corpus/cauda spermatozoa. Conclusions: This is the first characterization of expression and localization of Dysadherin in the male gonad and spermatozoa. Co-localization of Dys with Ecad and Na/K-ATPase in the sperm acrosome and flagellum suggests that Dys may be playing a role in the regulation of sperm physiology by modulating Ecad and Na/K-ATPase functions.