UMR BDR, INRA, ENVA, Université Paris Saclay, Jouy en Josas, France.
Reproduction. 2017 Nov;154(5):675-693. doi: 10.1530/REP-16-0057. Epub 2017 Aug 29.
Alteration of the postnatal phenotype has sparked great concern about the developmental impact of culture media used at fertilization. However, the mechanisms and compounds involved are yet to be determined. Here, we used the Ca responses from mouse eggs fertilized by ICSI as a dynamic and quantitative marker to understand the role of compounds in egg functioning and establish possible correlations with adult phenotypes. We computed 134 Ca responses from the first to the last oscillation in media with specific formulations. Analyses demonstrate that eggs generated two times as many Ca oscillations in KSOM as in M16 media (18.8 ± 7.0 vs 9.2 ± 2.5). Moreover, the time increment of the delay between two consecutive oscillations, named TIbO, is the most sensitive coefficient characterizing the mechanism that paces Ca oscillations once the egg has been fertilized. Neither doubling external free Ca nor dispermic fertilization increased significantly the total number of Ca oscillations. In contrast, removing Mg from the M16 boosted Ca oscillations to 54.0 ± 35.2. Hence, [Mg]/[Ca] appears to determine the number, duration and frequency of the Ca oscillations. These changes were correlated with long-term effects. The rate of female's growth was impacted with the 'KSOM' females having only half the fat deposit of 'M16' females. Moreover, adult animals issued from M16 had significantly smaller brain weight vs 'KSOM' and 'control' animals. TIbO is a new Ca coefficient that gauges the very early functional impact of culture media. It offers the possibility of establishing correlations with postnatal consequences according to IVF medium formulation.Free French abstract: A French translation of this abstract is freely available at http://www.reproduction-online.org/content/154/5/675/suppl/DC2.
卵母细胞受精后表型的改变引起了人们对受精时使用的培养基对胚胎发育影响的极大关注。然而，涉及的机制和化合物尚未确定。在这里，我们使用 ICSI 受精的小鼠卵母细胞的钙反应作为一个动态和定量的标记，来了解化合物在卵子功能中的作用，并建立与成年表型可能的相关性。我们计算了具有特定配方的培养基中第一次到最后一次振荡的 134 个钙反应。分析表明，KSOM 中的卵母细胞产生的钙振荡是 M16 培养基中的两倍（18.8 ± 7.0 对 9.2 ± 2.5）。此外，两个连续振荡之间的延迟时间增量，称为 TIbO，是描述一旦卵子受精，钙振荡的机制的最敏感系数。两倍的外部游离钙或二精受精并没有显著增加钙振荡的总数。相比之下，从 M16 中去除镁会使钙振荡增加到 54.0 ± 35.2。因此，[Mg]/[Ca]似乎决定了钙振荡的数量、持续时间和频率。这些变化与长期影响有关。雌性的生长速度受到影响，“KSOM”雌性的脂肪沉积只有“M16”雌性的一半。此外，来自 M16 的成年动物的大脑重量明显小于“KSOM”和“对照”动物。TIbO 是一个新的钙系数，它衡量培养基对早期功能的影响。它提供了根据 IVF 培养基配方建立与产后后果相关性的可能性。
