The trophoblast cells that take part in placenta formation are characterized by different modes of multiplication of their genome that largely designates their eu‐ or aneuploidy level. The two main ways of genome multiplication are described in different degree: (a) endoreduplication that involves almost complete shutdown of mitosis and (b) reduced mitosis (‘endomitosis’) in which, by contrast, entry into mitosis and the passage of its initial stages is a prerequisite of genome multiplication. Endoreduplication observed in the trophoblast giant cells (TGC) in a range of mammalian species implies uncoupling of DNA replication from mitosis achieved by reduction of mitotic Cdk activity. The key role in the regulation of endoreduplication and endomitosis play activity of APC/C complex, geminin and E2F family. A programme of genome multiplication and cell cycle progression may include depolyploidization achieved by specific mitotic or non‐mitotic (amitotic) division of the giant nucleus. In some mammalian species (Rodents), this process represents the final step of the giant cell lifespan that coincides with complete cessation of cell or genome reproduction. Meantime, in other species the process may take part in cell reproduction during lengthy pregnancy. The dynamics of fox and human polyploidization is similar by the possibility of a simultaneous increase in the proportion of endopolyploid and low‐polyploid cells. Reduced mitoses, endoreduplication and depolyploidization appear to be an evolution strategy allowing to generate the functionally different trophoblast cell populations depending of the lifestyle of life of the animal species. Some placental pathologies may be accounted for disturbance of the programme of the cell/genome reproduction of the giant and low‐ploid cell populations.

中文翻译：

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细胞周期和多倍体在不同哺乳动物胎盘滋养细胞中的作用。

参与胎盘形成的滋养层细胞的特征在于其基因组的多种繁殖方式，这些繁殖方式在很大程度上表明了它们的正或非整倍性水平。基因组繁殖的两种主要方式在不同程度上有所描述：（a）核内复制涉及几乎完全关闭的有丝分裂；（b）减少的有丝分裂（“内有丝分裂”），相比之下，进入有丝分裂及其初始阶段的通过阶段是基因组繁殖的前提。在一系列哺乳动物的滋养层巨细胞（TGC）中观察到的核内复制意味着通过减少有丝分裂Cdk活性而使DNA复制与有丝分裂脱钩。APC / C复合体，geminin和E2F家族在调节内复制和内吞作用中起关键作用。基因组繁殖和细胞周期进程的程序可能包括通过巨核的特定有丝分裂或非有丝分裂（有丝分裂）分裂实现的多倍体化。在某些哺乳动物物种（啮齿动物）中，该过程代表了巨细胞寿命的最后一步，这与细胞或基因组繁殖的完全停止相吻合。同时，在其他物种中，该过程可能会在长时间怀孕期间参与细胞繁殖。狐狸和人类多倍体化的动态是相似的，因为内多倍体和低倍体细胞的比例会同时增加。减少的有丝分裂，核内复制和去多倍体化似乎是一种进化策略，其允许根据动物的生活方式而产生功能不同的滋养层细胞群体。