Differential expression of gap-junction gene connexin 31 in seminiferous epithelium of rat testes

Spermatogenesis, a tightly regulated developmental process of male germ cel ls in testis, is associated with temporal and spatial expression of certain gap-junction connexins, Our findings by RT-PCR indicate that the Cx31 gene is expressed in testis tissue of adult and postnatal rats, During the post natal spermatogenic process, the Cx31-specific signal became detectable at 15 dpp and onward by in situ hybridization, and apparently localized in the basal compartment of seminiferous epithelium where active spermatogonia an d early primary spermatocytes reside. No signal was found in the luminal re gion. In adult testes, spermatids of elongation phase were also Cx31 positi ve. Immunohistochemical analysis with mouse anti-Cx31 antibody gave a simil ar staining pattern, providing further evidence that the gap-junction prote in is abundant in the basal seminiferous epithelium, in accordance with the cellular distribution of Cx31 mRNA, These results represent the first demo nstration of Cx31 expression at both transcriptional and protein levels in the seminiferous epithelium of rat testes. Thus, Cx31 may play a role in ce ll-cell communication during spermatogenesis. (C) 1999 Federation of Europe an Biochemical Societies.