EFFECTS OF THE BOOROOLA GENE FECB(B) ON SOMATIC AND GERM-CELLS OF THEFETAL TESTIS

The present study was conducted to compare in homozygous FecB(B)FecB(B )(BB) Booroola and ++ male fetuses, the body and the testicular growth s and the tissular and cellular compositions of the testis between 60 and 140 days of gestation. To eliminate differences in growth due to u terine environment, single embryos have been transferred in recipient Merinos d'Arles ewes. At 60 and 100 days of gestation, the body masses of BE fetuses were significantly lower than those of ++ foetuses (11 and 13%; P = 0.05); but their testis masses or their total contents of somatic (Leydig or Sertoli) cells did not differ significantly whatev er the fetal age. At 100 and 140 days of gestation, testis and body ma sses were significantly correlated without difference between BB and + genotypes. In conclusion, the presence or absence of homozygous gene FecB(B) does not induce significant differences in somatic or germ ce ll composition of the testis between 60 and 140 days of gestation.