Ozil J P, Huneau D
Unité de Biologie du Développement et Biotechnologies, INRA, France.
Development. 2001 Mar;128(6):917-28. doi: 10.1242/dev.128.6.917.
Postfertilization manipulation of mammalian embryos results in various developmental alterations. To determine whether the manipulation of the Ca2+ regime causing oocyte activation is a valuable experimental means in helping understand the biological process by which embryos integrate signals from outside and later regulate gene expression, we linked Ca2+ signal parameters i.e. amplitude, number and frequency, with the efficiency and quality of postimplantation development. Freshly ovulated rabbit oocytes were subjected to repetitive and modulated Ca2+ influx. The results provide three major pieces of information. Firstly, the Ca2+ stimulus is the most efficient signal activating mammalian eggs when it is applied in a repetitive manner, the amplitude being the crucial factor. Secondly, the dynamics of early cleavage does not appear to be determined by either the frequency or the amplitude of modulation of the Ca2+ signal that activates the oocyte. Thirdly, amplitude and temporal modulation of the Ca2+ signal in the early minutes influences the developmental performance and the morphology of the rabbit parthenogenetic conceptus at day 11.5 of pregnancy. The results demonstrate the importance of epigenetic events during postfertilization as well as the possible uses of Ca2+ modulation in studying long term developmental effects.
哺乳动物胚胎受精后的操作会导致各种发育改变。为了确定引起卵母细胞激活的Ca2+机制的操作是否是一种有价值的实验手段，有助于理解胚胎整合外部信号并随后调节基因表达的生物学过程，我们将Ca2+信号参数，即幅度、数量和频率，与着床后发育的效率和质量联系起来。对刚排卵的兔卵母细胞施加重复且调制的Ca2+内流。结果提供了三条主要信息。首先，当以重复方式施加Ca2+刺激时，它是激活哺乳动物卵子的最有效信号，幅度是关键因素。其次，早期卵裂的动力学似乎不是由激活卵母细胞的Ca2+信号的频率或调制幅度决定的。第三，怀孕第11.5天，早期几分钟内Ca2+信号的幅度和时间调制会影响兔孤雌生殖胚胎的发育性能和形态。结果证明了受精后表观遗传事件的重要性以及Ca2+调制在研究长期发育效应方面的可能用途。
