(A-L) Immunostaining of testis sections from mice treated with vehicle (A, C, E, G, I, and K) or rapamycin (B, D, F, H, J, and L) and euthanized at P4 (A, B, E, F, I, and J) or P8 (C, D, G, H, K, and L). Sections were stained with anti-DDX4 (A-D), anti-cleaved PARP1 (E-H), or double labeled with anti-BrdU (green, I-L) and anti-DDX4 (red, I-L). F-actin was stained with phalloidin (red, A-D or blue, E-H). Quantitation of the number of DDX4+(M and N) or the number of BrdU+/DDX4+ (O and P) cells from testes treated starting at P1 with vehicle or rapamycin and then euthanized at P4 (M and O) or at P8 (N and P). Asterisks indicate statistical significance with P≤0.01. Scale bar = 50 μM.