Defective spermatogenesis in <i>Scml2</i>^-/Y mice.

<p>(A) Western blot analysis of wild type and <i>Scml2</i>^-/Y testes. (B) Dramatic testis weight reduction (per pair of testes) in <i>Scml2</i>^-/Y mice. (C) Sharp reduction in sperm count (per pair of cauda epididymides) in <i>Scml2</i>^-/Y mice. The body weight of age-matched male mice was similar. Body weight at the 2-month age: wild type, 28.0 ± 1.5 g and <i>Scml2</i>^-/Y, 28.6 ± 1.0 g (n = 3 per genotype). Body weight at the 8-month age: wild type, 39.4 ± 4.7 g and <i>Scml2</i>^-/Y, 39.3 ± 5.5 g (n = 3 per genotype). (D) Histology of a 4-month-old wild-type testis at low magnification. (E-I) Variable spermatogenic defects in tubules from 4-month-old <i>Scml2</i>^-/Y testes. Testis section is shown in low magnification (E). Spermatogenesis in some tubules (F) is relatively normal. Apparently apoptotic spermatocytes are indicated by arrowheads (G). A layer of lost spermatocytes is marked by a dashed line (H). Some tubules (I) exhibit nearly complete depletion of pachytene spermatocytes. Vacuoles are indicated by arrows (I). Abbreviations (F-I): Pa, pachytene spermatocytes; RS, round spermatids; ES, elongated spermatids. Scale bars, 50 μm.