Three members of the Bcl-2 family of proteins (i.e., Bcl-2 itself, Bax, and Bad) all exhibited age-dependent levels of expression in the rat testis. A high level of Bcl-2 expression, localized immunohistochemically to the gono-cytes, was detected only in the youngest (i.e., 8-day-old) animals. Earlier studies have reported no significant expression of Bcl-2 in the rat or mouse testis, despite the fact that in transgenic animals overexpressing this protein, a pronounced degenerative effect on spermatogenesis occurs. Our results here indicate that Bcl-2 is expressed at significant levels by rat gonocytes before their further maturation into spermatogonia. In contrast, testicular expression of Bax and Bad was found in the present study to peak at 18 and 26 days of age, which is in agreement with earlier observations of mice and rats. buy allegra online
Employing immunohistochemical staining, Bad was localized primarily to Sertoli cells, confirming the earlier report of Yan et al..
A novel finding of the present study was that the Bax protein exhibits a distinctly stage-dependent localization in immature rat testis. In earlier studies, Bax has been revealed immunohistochemically to be present in Sertoli cells, spermatogonia, and spermatocytes. In the present investigation, intense expression of this proapoptotic protein was localized to pachytene spermatocytes in stages VII and VIII in 18- and 26-day-old rat testis.