Unfertilized Eggs Category

Our results also have implications for the time at which mouse eggs should be harvested after hCG administration for the purposes of conducting experiments aimed at understanding the molecular basis of fertilization. We suggest that eggs be harvested at a time shortly after ovulation (between 13 and 16 h post-hCG) in order to ensure that […]

The higher potassium concentration present in mouse tubal fluid as compared to culture medium is likely to increase the egg’s resting plasma membrane potential. This higher membrane potential in vivo could allow the opening of a small percentage of voltage-dependent calcium ion channels. This could result in a small influx of calcium that could account […]

A second important difference between eggs aged in vivo and in vitro to 22 h post-hCG was the status of the CGs. Unlike eggs in vivo, a large percentage of which undergo both anaphase onset and CG exocytosis, those residing in vitro from 13 to 22 h post-hCG underwent neither anaphase onset nor significant CG […]

The maintenance of elevated levels of p34cdc2 and MAP kinase activities in the cultured eggs may also account for their reduced ability to be activated by calcium ionophore in contrast to eggs that reside in the oviduct for a comparable period of time. Fertilization of mammalian eggs is accompanied by an initial calcium transient that […]

Whereas our previous study showed that increased time of residence in the oviduct of MII-arrested eggs is accompanied by progression toward the interphase-like state with the accompanying decrease in histone H1 and MAP kinase activities, CG loss and ZP modifications, recruitment of maternal mRNAs, and increased susceptibility to parthenogenetic activation, culture of eggs in vitro […]

Just as CG release increased with longer duration in vivo, the t50 increased similarly; e.g., eggs cultured from 16 to 22 h had a higher t50 than those cultured from 13 to 22 h. These results were consistent with inhibition of CG release and inhibition of progression toward the interphase-like state (Table 2). buy cheap […]

Effect of Culture on the Time-Dependent Changes in CG Exocytosis, ZP Modification, Recruitment of Maternal mRNAs, and Egg Activation The unanticipated observation that culture inhibited the progression toward the interphase-like state suggested that the other events of egg activation, i.e., CG exocytosis, the ZP modifications, and maternal mRNA recruitment, would also be prevented from occurring […]