Gonadal developmental defect of Ubb−/− mice. (A) Testis weights of Ubb+/+ and Ubb−/− mice at 7, 19, 28, and 40 days of age. Weights were measured from one testis per animal at each age (n ≥ 2/age). (B) (Top and middle) Morphology of testes (TS; indicated by black dotted circle) and seminal vesicles (SV; asterisk) in representative 5-month-old Ubb+/+ and Ubb−/− mice. (Bottom) Morphology of ovaries (OV; black dotted circle) in 5-month-old Ubb+/+ (n = 3) and UbB−/− (n = 3) mice. Fallopian tubes are indicated by asterisks. Scale bar for TS, 2 mm; scale bar for SV, 5 mm; scale bar for OV, 1 mm.