Figure 2
Huwe1 is a critical regulator of spermatogonial differentiation. (a) Disrupted formation of pre-leptotene spermatocytes in synchronized Stra8-Cre KO testis 48 days post retinoic acid (dpRA) adult testes. Representative immunohistochemical images from WT and Stra8-Cre KO testis sections stained for Stra8. Pre-leptotene spermatocytes are identified based on their Stra8 positivity and location in the seminiferous tubules away from the basement membrane. The yellow arrowhead indicates an A1 differentiating spermatogonia and the white arrow indicates a pre-leptotene spermatocyte. Scale bar = 90 μm. (b) Expression of markers for differentiating spermatogonia is decreased in synchronized Stra8-Cre KO 48 dpRA adult testes. Q-PCR analysis of markers of differentiating spermatogonia (Stra8, Dazl, Sohlh2) in the WT (n = 5) and Stra8-Cre KO (n = 6) testis. (c) Loss of pre-leptotene/leptotene spermatocytes (germ cells located away from the basement membrane) in synchronized Stra8-Cre KO 8 dpRA tubules. Hematoxylin and eosin stained testicular tissue sections from neonatal WT and Stra8-Cre KO mice. Scale bar = 90 μm. (d) Few pre-leptotene spermatocytes in the synchronized Stra8-Cre KO 8 dpRA testis. Representative immunofluorescence images of synchronized WT and Stra8-Cre KO testis stained for Stra8 (red) (top panel). Stra8 + cells at the basement membrane of tubule are A1 differentiating spermatogonia (arrowhead); Stra8 + cells away from the basement membrane are pre-leptotene spermatocytes (arrow). Quantification from the images (bottom panel). WT, n = 5 (135 tubules) Stra8-Cre KO, n = 7 (271 tubules). Scale bar = 20 μm. Data are shown as mean ± SEM. Student’s t-test. ***p < 0.001, *p < 0.05.
