(A) Gross analysis of testes from 7-week-old littermates. (B–M) Histological analysis of testes of Gasz
+/− and Gasz
−/− mice. (M) is a higher power magnification of (L) to show the lack of germ cells attached to the base of the tubule and sloughing germ cells in the lumen. G, spermatogonia; L, leptotene spermatocytes; M, meiotically dividing spermatocytes; Mit, mitotically dividing spermatogonia; P, pachytene spermatocytes, PL, preleptotene spermatocytes; Ser, Sertoli cells; Z, zygotene spermatocytes; dying spermatocytes with compact chromatin (red arrowhead); and with diffuse chromatin (open arrowhead); sloughing germ cells (black arrowheads). [Scale bars: 100 µm (B–C), 20 µm (D–K).]