Fig. 3

A–C Detection (A, B) and quantification (C) of germ cell apoptosis/DNA damage in wild-type (insl3^+/+) and insl3 knockout (insl3^−/−) testes 9 and 12 months post-fertilization. In A, white arrowheads and arrows indicate representative TUNEL⁺ spermatogonia and Sertoli cells, and gray arrowheads and arrows indicate representative TUNEL⁺ spermatids and spermatocytes, respectively. In B, representative TUNEL⁺ spermatogonia (SPG), spermatocyte (SPC) or spermatid (SPT) cysts are encircled with a white dashed line, and a TUNEL⁺ Sertoli cell (SC) is indicated by a white arrowhead. TUNEL⁺ cells/cysts are shown in green and propidium iodide (PI) counterstain is red. Scale bars, 25 µm. D Transcript levels of anti- (xiap) a pro-apoptotic (casp9) genes in insl3^+/+ and insl3^−/− testis tissue 9 and 12 months post-fertilization. TUNEL quantification results are shown as mean ± SEM (insl3^+/+ and insl3^−/−, 9 months: N = 4 and 7; insl3^+/+ and insl3^−/−, 12 months: N = 3 and 10; *p < 0.05; **p < 0.01), and gene expression data as mean fold change ± SEM (insl3^+/+ and insl3^−/−, 9 months: N = 8 and 7; insl3^+/+ and insl3^−/−, 12 months: N = 6 and 10; *p < 0.05) and expressed relative to the wild-type group (which is set at 1).