Figure 3. TUT4/7 and their uridylation activity are required for male fertility and pachytene progression.

a, Western blots from whole testes extracts of Tut4/7^CTL, Tut4^-/-, Tut7^-/-, and Tut4/7^cKO animals using anti-TUT4, TUT7, AGO2 and SMC1A antibodies. b, Pups per plug for Tut4/7^CTL, Tut4/7^cKO and Tut4/7^cAAD males mated with WT females. The numbers of plugs and sires for each group are indicated. Each dot represents a single litter size. The mean, and standard deviations are indicated in red, together with the groups’ difference significance (****P < 0.001, Wilcoxon test two-sided). c, Testis weight of Tut4/7^CTL, Tut4/7^cKO and Tut4/7^cAAD mice. Each dot corresponds to a single testis. The center value represents the mean, and the error bars the standard deviation (****P < 0.001, Wilcoxon test two-sided; Tut4/7^CTL, n=28; Tut4/7^cKO, n=28; Tut4/7^cAAD, n=15). d, Sperm count per epididymis of Tut4/7^CTL, Tut4/7^cKO and Tut4/7^cAAD animals. Each dot corresponds to the sperm count from a single epididymis. The center value represents the mean, and the error bars the standard deviation (****P < 0.001, Wilcoxon test two-sided; Tut4/7^CTL, n=8; Tut4/7^cKO, n=8; Tut4/7^cAAD, n=8). e, Sections of epididymis from Tut4/7^CTL, Tut4/7^cKO and Tut4/7^cAAD animals stained with Hematoxylin and Eosin. Scale bar, 120 μm. f, Sections of stage IX-X tubules from Tut4/7^CTL, Tut4/7^cKO and Tut4/7^cAAD mice stained with the PAS method. The different cell layers are indicated: stages IX-X elongated spermatids (ES), pachytene (P), leptotene (L). Apoptotic cells are also indicated (Ap). On the left, a schematic representation of the different layers found in a stage IX-X tubule is shown. Scale bar, 10 μm. g, Tubule sections from Tut4/7^CTL, Tut4/7^cKO and Tut4/7^cAAD animals stained with TUNEL. DNA was stained with Hoechst 33342 (blue). Scale bar, 10 μm. Cell types are indicated as in f.