Fig. 5. Decreased proliferation in Pin1^-/- PGCs. (A-C) Male XY; (D-F) female XX. (A,B,D,E) Confocal images of 12.5 dpc male (A,B) and female (D,E) gonads after wholemount immunohistochemistry. (A,D) Many PGCs (green, round cells) incorporated BrdU (red, solid arrows) in wild-type gonads. (B,E) Few Pin1^-/- PGCs were labeled with BrdU (red, solid arrows) in the same period, while many Pin1^-/- PGCs did not incorporate BrdU (broken arrows). (A,B) Pin1^-/- Sertoli cells (arrowheads) appeared to be labeled with BrdU similar to wild type. (C,F) Bar graphs of BrdU labeling indices of wild-type (solid) and Pin1^-/- (hatched) male XY (blue) and female XX (pink) PGCs. Values represent mean±s.e.m. *Statistically significant using unpaired Student's t-test, P<0.001.