FIG. 1.

TR4 is cell-specifically expressed in pachytene spermatocytes and stage-dependently expressed in round spermatids. (A) In situ hybridization of normal adult testis sections with antisense TR4 digoxigenin-labeled probe. Seminiferous tubules in stages IV and VII, which show positive signals in pachytene spermatocytes and in both pachytene spermatocytes and spermatids, respectively, are shown. (B) PAS and hematoxylin staining of two seminiferous tubules in panel A, in a consecutively cut section. Sections from three TR4^+/+ and TR4^−/− mice were examined. A representative slide is shown in each panel. Ps, pachytene spermatocytes; Rs, round spermatids; PL, prelepotene spermatocytes. Magnification, ×400.