| pubmed-article:4601603 | pubmed:otherAbstract | PIP: Ovulation of the collared lemming occurred approximately 9 hours after copulation or injection of HCG. During long periods of estrus, ovulation did not occur spontaneously, but was induced by copulation during estrus. Induction of ovulation was independent of the time of day at which copulation occurred. Between the time of copulation and 8 hours later, preovulatory follicles increased in size. Following copulation, meiotic changes in the ova of preovulatory follicles proceeded rapidly and 1 hour after copulation, the nuclear membranes had almost disappeared. The first meitoic metaphase was evident 2 hours after copulation. In some eggs, the first mitotic division had occurred 24 hours after copulation. | lld:pubmed |
