Fig. 5. Compromised fertility of Ror2^{W749FLAG/W749FLAG} males. (A) Percentage of test females that became plugged or pregnant after controlled mating with Ror2^+/W749FLAG (gray bars, HET) or Ror2^{W749FLAG/W749FLAG} (black bars, KI) littermate mice. Values are mean±s.e.m. (n=60 matings, 10 matings per male). (B) Relative combined testicular weight, expressed as a per mille () of body weight (BW), in Ror2^{W749FLAG/W749FLAG} (black bars, KI) and control (gray bars, HET) littermates. Values are mean±s.e.m. (n=6, 2- to 3-month-old males). Significantly different from controls: ^**P<0.01; ^*P<0.05. (C-F) Histology of heterozygous (C,E) and homozygous (D,F) Ror2^W749FLAG testes from 16-day-old animals. The homozygous gonad exhibited decreased tubular density, with seminiferous tubules containing a single cell layer (asterisk). (G-I) Histology of a Ror2^{W749FLAG/W749FLAG} testes (2-month-old) showing a focal area of tubular degeneration (G, arrow). (H) High magnification of a normal seminiferous tubule in the mutant testis. (I) High magnification of an abnormal seminiferous tubule, lined by clumps of Sertoli cells along the basal membrane and devoid of spermatogonia or spermatids.