A detailed analysis of early events during in-vitro fertilization of bovine follicular oocytes

Abstract

Summary. Bovine

Blastocyst formation by pig embryos resulting from in-vitro fertilization of oocytes matured in vitro

“…One of the reasons for the high level of asynchrony observed in this study may therefore be the incompleteness of capacitation of sperm¬ atozoa in vitro. Another reason may be the various amounts of a cytoplasmic substance responsible for male pronucleus formation in oocytes, as suggested by Xu & Greve (1988).…”

In vitro fertilization in cattle: a review

“…This activation is apparently an age-dependent process (Ware et al, 1989). It (Xu et al, 1988b) (Lu et al, 1987;Fukui et al, 1989;Leibfried-Rutledge et al, 1989;Lu et al, 1989) or rabbit oviducts (Fukui and Ono, 1988;Fukui et al, 1989). However, methods of in vitro culture that utilize coculture with bovine oviduct epithelial cells (BOEC) (Fukui and Ono, 1988;Fukui et al, 1989;Eyestone and First, 1989a;Gordon and Lu, 1990;Madison et al, 1991 granulosa cells (Goto et al, 1988;Berg and Brem, 1989), trophoblastic vesicles (Heyman and M6n6zo, 1987;Aoyagi et al, 1989) or culture in conditioned medium (Eyestone and First, 1989a) are very effective and have become the preferred method for the culture of embryos produced in vitro.…”

Delay in Ovulation and Fertilization and Asynchronous Pronuclear Development in Aged Hamsters.

“…The sequence of sperm penetration into ooplasm, sperm head decondensation, completion of the second meiotic division, and male and female pronuclear development were recorded and classified microscopically into five developmental stages as shown in Table 1. The criteria were modified for hamster ova in this study, based on the report on bovine oocytes fertilized in vitro by Xu and Greve [22].…”

“…Table 3 shows synchrony/asynchrony of the male and female pronuclei. According to Xu and Greve [22], the ovum having two pronuclei at identical stages or exhibiting only one stage difference was regarded as representing synchronous development of male and female pronuclei. On the other hand, the ovum, with pronuclei which were two or more stages apart, was regarded as asynchronous.…”