CHROMOSOME ABNORMALITIES IN RABBIT PREIMPLANTATION BLASTOCYSTS INDUCED BY SUPEROVULATION

Abstract

While there are undoubtedly multiple causes of spontaneous abortion and congenital birth defects, high incidences of chromosomal abnormalities in human abortuses (Carr, 1965; Geneva Conference, 1966; Makino & co-authors, 1967; Ikeuchi, Sasaki, Kohno, Hayata & Fujimoto, 1972), and in early embryos of the pig (McFeely, 1967) suggest that chromosomal imbalance may be one of the primary causes of early embryonic death. Excessive administration of HCG has been reported to affect sperm capacitation in rabbits (Soupart, 1967; Wettemann & Hafs, 1970), and the development of the zona pellucida in baboons (Katzberg & Hendrickx, 1966). Recently, a high incidence of triploid embryos has been associated with PMSG-HCG-induced superovulation in mice (N. Takagi, personal communication). The present investigation was conducted to study the effect of superovulation on the karyological constitution of preimplantation rabbit blastocysts. Nine mature nulliparous female