Connexin43 Gene Expression and Regulation in the Rodent Seminiferous Epithelium

Abstract

Connexin43 (Cx43) is one of the most predominant gap junction proteins found in the testis. We used in situ hybridization and indirect immunofluorescence to study the distribution of Cx43 mRNA and protein in the rodent seminiferous epithelium. During mouse testis maturation, Cx43 mRNA and its corresponding protein were first detected in the adluminal compartment of the growing seminiferous tubules (early postnatal age: Day 12) to become progressively located in the basal compartment at later ages (Days 16, 19, 27). In seminiferous tubules of sexually mature animals, the intensity of the hybridization signal was stage-dependent, with a maximum at Stage VII compared with Stages V and IX of the spermatogenic cycle (ppp<0.05) and undetectable in older animals. These data provide new information about the precise localization of Cx43 mRNA and protein in seminiferous tubules of immature and mature rodent testes. Moreover, they suggest that retinoids, through the RXRβ receptors, could be involved in the control of Cx43 gene expression in Sertoli cells.