(A-F) Immunostaining of testis sections from mice treated with vehicle (A, C, and E) or rapamycin (B, D, and F) and euthanized at P4. Sections were stained with anti- phosphorylated RPS6 (A and B), anti- phosphorylated EIF4EBP1 (C and D), or total FOXO1 (E and F). F-actin was stained with phalloidin (red) to visualize testis cords. Scale bar = 50 μM.