Greenwood J, Costanzo V, Robertson K, Hensey C, Gautier J
Department of Genetics and Development and Department of Dermatology, Columbia University, 630 West 168th Street, New York, NY 10032, USA.
Novartis Found Symp. 2001;237:221-30; discussion 230-4. doi: 10.1002/0470846666.ch17.
Xenopus embryos divide rapidly following fertilization. During this rapid period of cleavage, cell divisions are not sensitive to DNA replication or spindle assembly inhibition. Here, we have investigated the consequences of eliciting DNA damage in these embryos. We show that the rapid cell divisions are not affected by DNA damage. However, as the embryos reach the onset of gastrulation, they undergo rapid and synchronous apoptosis. We have investigated the regulation on this delayed apoptotic response to DNA damage. Next, we have reconstituted a DNA damage cell cycle checkpoint in vitro, demonstrating that all the checkpoint signalling components are present in the embryos but are not activated under the experimental conditions used to generate DNA damage in the embryo.
非洲爪蟾胚胎在受精后迅速分裂。在这个快速分裂期，细胞分裂对DNA复制或纺锤体组装抑制不敏感。在这里，我们研究了在这些胚胎中引发DNA损伤的后果。我们发现快速的细胞分裂不受DNA损伤的影响。然而，当胚胎进入原肠胚形成期时，它们会经历快速且同步的凋亡。我们研究了对这种DNA损伤延迟凋亡反应的调控。接下来，我们在体外重建了一个DNA损伤细胞周期检查点，证明所有检查点信号成分在胚胎中都存在，但在用于在胚胎中产生DNA损伤的实验条件下未被激活。
