CONICET | Buscador de Institutos y Recursos Humanos

tapa con imagen de articulo http://molehr.oxfordjournals.org/content/vol14/issue10/cover.dtl Epithelial cadherin (E-cadherin) has been involved in several calcium dependent cell-cell adhesion events; however, its participation in gamete interaction has not been fully investigated. Our results have demonstrated expression of E-cadherin mRNA in the human male reproductive tract, showing higher levels in the caput, corpus and cauda epididymis than in the testis. The mature 122-KDa E-cadherin was detected in epididymal protein extracts, and was localized in the epithelial cells from the three epididymal regions. Moreover, the 86-KDa E-cadherin ectodomain was found in cauda epididymal and seminal plasma. Western immunoblotting of human sperm protein extracts allowed the identification of four E-cadherin forms (122, 105, 97 and 86 KDa). The protein was localized in the acrosomal region of intact spermatozoa, it remained associated to the head of acrosome-reacted cells, and was also detected in the egg surface. A similar localization was determined for other proteins of the adhesion complex (b-catenin and actin). Spermatozoa incubated with anti E-cadherin antibodies showed impaired binding to homologous Zona Pellucida (ZP); in addition, presence of these antibodies inhibited the penetration of human spermatozoa to ZP-free hamster eggs. The results here presented thoroughly describe the expression of E-cadherin in the male reproductive tract and gametes, and strongly suggest its involvement in adhesion events during human fertilization. The identification of proteins involved in gamete interaction will contribute to the understanding of the molecular basis of fertilization and help in the diagnosis and treatment of infertility.