histological study of testicular biopsies from infertile men showing sertoli-cell-only tubules due to hypogonadotropic hypogonadism , cryptorchidism , oestrogen treatment , chemotherapy or del castillo 's syndrome , revealed four types of sertoli cells : ( 1 ) normal adult mature cells showing an indented nucleus , grossly triangular in shape with a prominent tripartite nucleolus ;
C0007610
nucleus
C0007609
nucleolus