Interspecies pregnancy of Spanish ibex (Capra pyrenaica) fetus in domestic goat (Capra hircus) recipients induces abnormally high plasmatic levels of pregnancy-associated glycoprotein.

摘要

Spanish ibex females were superovulated with 9 mg NIADDK-oFSH-17 and embryos were surgically collected 5.5 days after oestrus. Two embryos were transferred per recipient. Domestic goat recipients were previously mated to vasectomized domestic bucks(17 females; interspecific-monospecific gestations) or to fertile males (9 females; interspecific-bispecific gestations). Intraspecific pregnancies were obtained by natural mating between males and females of the same species (6 Spanish ibex; 1 domesticgoat). Pregnancy rate diagnosed by blood progesterone concentration was low in both interspecific-monospecific (7/17) and interspecific-bispecific (3/9) transfers. None of the monospecific (0/7) and 2 (2/3) of the bispecific pregnancies developed to term. The pregnancy-associated glycoprotein (PAG) profile of ibexes carrying an ibex fetus showed 2 similar peaks of 60-70 ng/ml on days 34 and 153 of pregnancy, while that of goats carrying a goat fetus had the maximum value (60-70 ng/ml) at day 50, decreasing slightly until parturition. Dams with mixed-species gestations (ibex + goat in goat) showed a first peak of 500-1000 ng/ml on day 70 and a second (200-500 ng/ml) on day 140 of pregnancy. Four ibex-in-goat gestations that terminated with the expulsionof dead fetuses at days 110-170 had their maximum PAG values (100-700 ng/ml) on days 60-90. It is concluded that it is possible to achieve pregnancies after transfer of ibex embryos into domestic goats, that such pregnancies are associated with a markedchange in the PAG profile, and that live ibex kids can be produced when embryos from both species share the uterus.