Lack of cell cycle checkpoints in human cleavage stage embryos revealed by a clonal pattern of chromosomal mosaicism analysed by sequential multicolour FISH
Lack of cell cycle checkpoints in human cleavage stage embryos revealed by a clonal pattern of chromosomal mosaicism analysed by sequential multicolour FISH
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DOI：
10.1017/s0967199400001015
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发表时间：
2000-08-01
期刊：
影响因子：
1.7
通讯作者：
Ogilvie, CM
中科院分区：
文献类型：
--
作者：
Harrison, RH;Kuo, HC;Ogilvie, CM
多色荧光原位杂交（FISH）分析分裂期人类胚胎的间期核，突出了高发病率的合子后染色体镶嵌，包括非整倍体和倍性镶嵌。事实上，一些胚胎似乎在大多数细胞核中具有混乱的染色体互补，这表明细胞周期检查点可能在早期卵裂中不起作用。然而，这些研究中的大多数仅分析了有限数量的染色体（3-5），使得难以区分FISH伪像与真正的非整倍体。我们现在报告分析11条染色体在五个连续的杂交与标准组合的两个或三个探针和最小的损失杂交效率。对一系列被捕获的人类胚胎的分析揭示了一种基本一致的杂交模式，在该模式上叠加了两个或多个细胞核中特定对的一条或两条染色体的频繁缺失，这表明克隆起源和染色体丢失后的持续分裂。在以三倍体XXX胚胎为主的双核细胞中，两个细胞核在制备过程中保持附着，并且所分析的每个染色体的混沌二倍体/三体状态对于每个细胞核都是相同的。此外，在每次杂交中，信号分布为关于附着平面的镜像，表明后期期间的过早解凝聚与缺乏检查点控制一致。
Multicolour fluorescence in situ hybridisation (FISH) analysis of interphase nuclei in cleavage stage human embryos has highlighted a high incidence of postzygotic chromosomal mosaicism, including both aneuploid and ploidy mosaicism. Indeed, some embryos appear to have a chaotic chromosomal complement in a majority of nuclei, suggesting that cell cycle checkpoints may not operate in early cleavage. Most of these studies, however, have only analysed a limited number of chromosomes (3-5), making it difficult to distinguish FISH artefacts from true aneuploidy. We now report analysis of 11 chromosomes in five sequential hybridisations with standard combinations of two or three probes and minimal loss of hybridisation efficiency. Analysis of a series of arrested human embryos revealed a generally consistent pattern of hybridisation on which was superimposed frequent deletion of one or both chromosomes of a specific pair in two or more nuclei indicating a clonal origin and continued cleavage following chromosome loss. With a binucleate cell in a predominantly triploid XXX embryo, the two nuclei remained attached during preparation and the chaotic diploid/triphoid status of every chromosome analysed was the same for each nucleus. Furthermore, in each hybridisation the signals were distributed as a mirror-image about the plane of attachment, indicating premature decondensation during anaphase consistent with a lack of checkpoint control.