Spontaneous ovarian teratomas in DAZL-deficient pigs. (A) The pig is an outgroup to rodents and primates, sharing a common ancestor 95 million years ago (red dot). (B) Ovarian teratoma (arrow) in DAZL-deficient pig. The tumor measured 46 × 23 × 28 cm and weighed 15.4 kg. (C) Incidence of ovarian teratomas in control and DAZL-deficient pigs. ***P value < 0.0001 using Fisher’s exact test. (D) Representative histology of teratoma from ovary, stained with PAS. (E) Histology of control (Left, 18 wk, spermatocytes marked with arrow head) and DAZL-deficient testis at 11 wk (Center) and 9 mo of age (Right), stained with PAS. (F) Immunofluorescence of control (Left, 18 wk) and DAZL-deficient pig testis (Right, 11 wk). Germ cells were stained with DDX4 (green), and somatic cells were stained with SOX9 (magenta). DNA was stained with DAPI (blue). (Scale bars, 50 µm.)