Fig. 2
Aberrant spermiogenesis and apical actin cytoskeleton disorganization could be detected in Amh-pa1−/− mice. a PAS staining of testes sections from 8-week-old Pa1F/F and Amh-pa1−/− mice. Elongated spermatids were gradually lost along with spermiogenesis. Different colored arrows indicated different types of cells. Z: Zygotene; eST: elongating spermatid; M: meiotic spermatocyte; P: pachytene spermatocyte; rST: round spermatid. b PAS staining of spermatids at different developmental stages from 8-week-old Pa1F/F and Amh-pa1−/− mice. Deformed spermatid head shaping begins to appear at Step 9 (asterisk) in Amh-pa1−/− testes. c F-actin in the apical compartment of seminiferous tubules was seen to be perturbed and disorganized in adult Amh-pa1−/− testes. Arrows indicate F-actin bundles. Immunofluorescence using FITC-labeled phalloidin (green) was performed on seminiferous tubules of Pa1F/F mice (upper) and Amh-pa1−/− mice (lower). Nuclei were stained with DAPI (blue). Dashed boxes showed localization of the enlarged images. Dashed curve indicated basal membrane of seminiferous tubules in the left images and F-actin structure surrounding the sperm head in the right enlarged images. d Seminiferous tubule sections of Pa1F/F and Amh-pa1−/− testes were stained for WT1 and TUNEL probe and the nuclei were stained with DAPI. 
, WT1 positive Sertoli cells (red); 
, TUNEL positive cells (green). Dashed boxes showed localization of the enlarged images. Dashed circle and curve indicated basal membrane of seminiferous tubules. e More TUNEL positive tubules were observed in Amh-pa1−/− testis compared with Pa1F/F testis and f more TUNEL positive cells per tubule were observed in Amh-pa1−/− testis compared with Pa1F/F testis. (n = 3). Data are presented as mean ± SEM. ***p < 0.001, ****p < 0.0001