Fig. 1
Specific knockout of Pa1 in Sertoli cells impairs spermatogenesis. a PA1 was predominantly localized in the nucleus of human Sertoli cells. Immunohistochemistry (IHC) image of PA1 in normal adult human testis. Dashed boxes showed localization of the enlarged images. Arrows indicated the nuclei of Sertoli cells. b PA1 was highly expressed in testis compared with other murine organs. The expression profile of PA1 in different murine organs (8-week-old) using immunoblot. c PA1 mainly localized in the nuclei of Sertoli cells in mouse testis. Seminiferous tubule sections of wild-type testes (5-week-old) were co-stained for Sertoli cell marker WT1 (green), PA1 (red) and DAPI (blue). Enlarged images are shown on the lower panel. Dashed circle and curve indicated basal membrane of seminiferous tubules. Arrows represents cells that are positive for PA1 and/or WT1. 
, Leydig cell; 
, SPG; 
, SPC; 
, SC. d PA1 protein levels dramatically decreased in the testes (8-week-old) of Amh-pa1−/− mice. Immunoblotting of PA1 in Pa1F/F and Amh-pa1−/− testes. GAPDH as the loading control. e 8-week-old Amh-pa1−/− mice could not fertilize the female mice. After mating, 88.33 ± 4.41% of wild-type female mice were pregnant after crossing with Pa1F/F males, while none of wild-type female mice crossing with Amh-pa1−/− mice became pregnant. (n = 3). Data are presented as mean ± SEM. ****p < 0.0001. f The average litter size of Pa1F/F males and Amh-pa1−/− mice at 8-week-old (n = 3 independent experiments). Data are presented as mean ± SEM. ****p < 0.0001. g Histological analysis of the caudal epididymis of Pa1F/F and Amh-pa1−/− mice. Enlarged images are shown in the lower panel. Dashed boxes showed localization of the enlarged images. Debris of immature spermatozoa are indicated with black arrows. h The volume of testes of 8-week-old Amh-pa1−/− mice was significantly smaller than that of Pa1F/F mice. i The ratio of testis weight/body weight of Amh-pa1−/− mice was significantly lower than that of Pa1F/F mice (n = 5). Data are presented as mean ± SEM. ****p < 0.0001. j Histological analysis of the testis of 8-week-old Pa1F/F and Amh-pa1−/− mice. (a, b) Two seminiferous tubules are shown for the Pa1F/F mice with enlarged images shown on the right. (c) An empty seminiferous tubule is shown for the Amh-pa1−/− mice with an enlarged image shown on the right. The enlarged image shows an empty tubule indicated with an asterisk. Germ cells could not be found in these seminiferous tubules. (d) A degenerated seminiferous tubule is shown for the Amh-pa1−/− mice with an enlarged image shown on the right. The enlarged image shows a degenerated tubule indicated with an asterisk. Decreased germ cells are found in these seminiferous tubules. k The average diameter of seminiferous tubules of 8-week-old Amh-pa1−/− mice were significantly lower than those of 8-week-old Pa1F/F mice. (n = 3). Data are presented as mean ± SEM. **p < 0.01