Beschreibung:
Abstract: Using an anti‐Fos family member antiserum, we previously described, in the testis of Rana esculenta, the presence of a nuclear 43‐kDa protein that we hypothesized to be Fra‐1. Using an antiserum against Fra‐1, we here report on Fra‐1 expression, localization, and putative activity in the R. esculenta testis during the annual reproductive cycle. Western blot analysis confirms that the nuclear 43‐kDa protein is Fra‐1. Immunocytochemistry demonstrates Fra‐1 in peritubular myoid cells (PMC), efferent ducts, and blood vessels. We present, for the first time for a vertebrate, experimental evidence that the expression of Fra‐1 in PMC is related to its activity during sperm transport from the tubular compartment to the efferent ducts.