Testicular Expression and Distribution of the Rat Bcl2 Modifying Factor in Response to Reduced Intratesticular Testosterone

Abstract The Bcl2 modifying factor (Bmf) is a pro-apoptotic member of the Bcl2 family of apoptosis-related proteins that has been shown to initiate apoptosis in response to the loss of attachment of cells from their basal lamina (anoikis). Experimental reduction in intratesticular testosterone concentration brings about the death of spermatids as a consequence of their sloughing from Sertoli cells. Given the role of Bmf in anoikis in other systems, we hypothesized that Bmf would be expressed in germ cells and that its expression and normal distribution might be altered under conditions that induce widespread germ cell loss. To test these hypotheses, we demonstrated that Bmf indeed is expressed in the testis and cloned the full-length rat Bmf cDNA. Immunohistochemistry revealed that Bmf is present in the subacrosomal space of postmeiotic spermatids from step 4 to 16 of spermiogenesis. To test the hypothesis that Bmf expression and distribution are altered by conditions that elicit anoikis, intratesticular ...