Fig. 4

Targeted disruption of ar in zebrafish causes male infertility due to defective spermatogenesis. (A-C) Gross appearance of testes from wildtype (ar ^+/+), heterozygous (ar ^+/-) and homozygous (ar ^-/-) (ar ^{ihb1225/ihb1225}) zebrafish. Testes of ar ^-/- male zebrafish was smaller and more transparent compared with that in their ar ^+/+ or ar ^+/- male siblings. (D) Gonadosomatic index (GSI) in ar^+/+ and ar^-/- male zebrafish. (E) Sperm motility evaluation under a dark-phase microscope. (F, G) Histology of testes from wildtype (ar ^+/+) and homozygous (ar ^-/-) (ar ^{ihb1225/ihb1225}) zebrafish at 3 mpf. Compared with wildtype sibling testes, spermatogenesis in ar ^-/- testes was delayed as indicated by more spermatogonia (SG), fewer spermatocytes (SC) and fewer spermatozoa (SZ); the spermatogenetic cysts were smaller; and spermatogenesis was arrested at the second meiosis. (H, I) Toluidine blue staining testes from wildtype (ar ^+/+) and homozygous (ar ^-/-) (ar ^{ihb1225/ihb1225}) zebrafish at 3 mpf. Compared with wildtype sibling testes, the size of spermatogonia (SG) was bigger and the number of Sertoli cells was increased in ar ^-/- testes. Leydig cells (LC) and lumen are indicated. Dpf, days post fertilization; Mpf, months post fertilization.