Fig. 4.

Acrosome formation is impaired during Vps13b^{∆Ex3/∆Ex3} spermiogenesis. a Representative images of PAS-stained testicular sections at tubule stages II, III, V–VII, and X–XII. Arrows point at PAS-positive acrosomal figures in wild-type spermatids and faint dot-like PAS signal in mutant spermatids. Spd(E) early spermatid, Spd(L) late spermatid. Scale bars 50 µm. b Electron micrographs of Golgi, cap, acrosome, and maturation phases of wild-type and mutant spermatids. G golgi, AV acrosomal vesicle, AG acrosomal granule, AC acrosome, N nuclei, CN condensed nuclei, NDL nuclear dense lamina, M mitochondria