The initiation of DNA replication in mammalian cells is a highly coordinated process that ensures duplication of the genome only once per celldivisioncycle.
哺乳动物细胞的DNA复制启动是一个高度协调的过程，从而保证了每次细胞分裂中基因组只复制一次。
2
Wilmut said there were so many failures because it was difficult to ensure that the empty oocyst and the donor cell were at the same stage of the celldivisioncycle.
威尔·马特说之所以有这么多的试验失败，是因为很难保证空卵囊和供体细胞能处在细胞分裂周期的同一阶段。
3
CellCycle Progression through the celldivisioncycle and transitions between various phases are regulated by using CDC25 phosphatases to activate specific cyclin-dependent kinase(CDK) complexes.