| One plausible strategy to fertilize horse oocytes in vitro is to duplicate the nuclear maturation and cumulus expansion of periovulatory oocytes which occurs in vivo. The nuclear maturation of postovulatory mare oocytes appears to be either metaphase I, metaphase II, or both metaphase I and II. A large mass of cumulus with completely expanded outer cumulus and corona cells surrounds the equine oviductal oocyte at the time of fertilization. The objectives of this study were to test the hypotheses that FSH, hCG, and fetal calf serum (FCS), equine follicular fluid, prostaglandin E;FSH, hCG, and FCS induced nuclear maturation in expanded complexes and cumulus expansion in compact and expanded complexes. Also, follicular fluid caused additional improvement in the degree of oocyte maturation in compact complexes and cumulus expansion in compact and expanded complexes. PGE... |
