Representative images ( E ) and quantification ( F ) of the cell cycle distribution of PGCs (STELLA + ), assessed by co-staining for Cyclin B1 and EdU, in Faap100 + / + and Faap100 -/- genital ridges at E11.5. n = 4/4 embryos (1306/656/1046/506; 341/128/337/398 PGCs). In this system, Cyclin B1-negative cells are in G1 phase; EdU-positive cells are in S phase; cells expressing Cyclin B1 in the nucleus are in M phase; and the remaining cells expressing Cyclin B1 in the cytoplasm are in G2 phase. Scale bars, 50 m. Data are shown as the mean SD ( C , D , F ). Unpaired two-tailed Student’s t -test ( C , F ) and two-tailed Mann–Whitney U -test ( D ), ns, not significant, ** P < 0.01 and *** P < 0.001
