Fig. 2

A–C Body weight (A), gonado-somatic indices (GSI; B) and testicular morphology (C) of wild-type (insl3^+/+) and insl3 knockout (insl3^−/−) males 9 and 12 months post-fertilization. Data are mean ± SEM (insl3^+/+ and insl3^−/−, 9 months: N = 8 and 13; insl3^+/+ and insl3^−/−, 12 months: N = 8 and 15; p < 0.05; **p < 0.01; ***p < 0.001). In C, yellow dashed lines indicate representative apoptotic germ cell cysts. Scale bars, 25 µm. D, E Quantitative analysis of spermatogenesis (D) and transcript levels of growth factors, steroidogenesis-related and Insl3 receptors (E) in 12 months-old insl3^+/+ and insl3^−/− adult testis tissue. Data are mean ± SEM (insl3^+/+ and insl3^−/−: N = 6 and 10; *p < 0.05; **p < 0.01) and, in E, expressed as relative to the wild-type group (which is set at 1; dashed line). A_und, type A undifferentiated spermatogonia; A_diff, type A differentiating spermatogonia; B, type B spermatogonia; SPC, spermatocytes; SPT, spermatids; SPZ, spermatozoa; Others, including (i) empty spaces lined by Sertoli and/or germ cells that are not part of the lumen, (ii) Sertoli cell only areas, and (iii) apoptotic cells (see Supplementary Fig. 2 for further details); SC, Sertoli cell; LC, Leydig cell.