Oocyte quality in pigs is defined as the potential of that oocyte to develop into a viable offspring. There is increasing evidence that the programming of the oocyte must be completed before leaving the ovarian follicle, including both nuclear and cytoplasmic maturation. Pig oocytes matured in vitro under basic conditions are deficient in some, as yet unidentified, cytoplasmic factors and thus ...

STUDY QUESTION What proportion of pregnancies are a result of ovum transmigration after salpingectomy for ectopic pregnancy? SUMMARY ANSWER Approximately one-third of spontaneously conceived pregnancies are a result of pick-up of the ovum from the ovary contralateral to the remaining tube in women with a history of salpingectomy. WHAT IS KNOWN ALREADY The corpus luteum has been found contra...

In the process of fertilization, most mammalian spermatozoa must penetrate through a series of egg investments before reaching the vitelline membrane. By contrast, cock spermatozoa have only to penetrate the vitelline membrane of the hen's ovum. The composition of the vitelline membrane of the hen's ovum at the time of ovulation has been described by Bellairs, Harkness & Harkness (1963) as a si...

Eight ewes in each of four groups were injected subcutaneously immediately prior to natural mating with 0, 30, 150, or 750 /ag of estradiol-17/3. The ewes were necropsied 3 days after mating and the ova were examined. None of the three doses of estradiol reduced ovum fertilization significantly, but the 750-/ag dose decreased the number of accessory sperm ceils in the zonae pellucidae. Eight ot...

background: chromosomal disorders are the most common cause of first trimester spontaneous abortion. among the human chromosomes, chromosome no.9 was the most common structural chromosomal variant and it is not thought to be of any functional importance, which often considers as a normal variation in structural polymorphisms, nevertheless there are some studies which claim that there is an asso...