Fig. 2. Loss of the full-length isoform of Brca1 does not interfere with the mitotic phase of spermatogenesis. Immunolocalization of GCNA in p53^+/- control (A,C,E) and Brca1^/p53^+/- mutant (B,D,F) testes at P10 (A,B), P16 (C,D) and P21 (E,F). In control testes, early pachytene spermatocytes located inside the lumen (arrows) and premeiotic cells located along the base of tubules (arrowheads) are GCNA positive. By contrast, spermatocytes inside the lumen of Brca1 mutant testes are all positive for GCNA (arrows and arrowheads, B,D,F). Anti-BrdU (G,H), and anti-phosphorylated H3 (I,J) staining in testes from 6-week-old control (G,I) and mutant (H,J) mice. Arrows in G-J indicate BrdU-positive cells (G,H) and phosphorylated H3-positive cells (I,J).