Vázquez-Diez Cayetana, FitzHarris Greg
Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada.
Département d'Obstétrique-Gynécologie, Faculté de Médecine, Université de Montréal, Montréal, QC, Canada.
Methods Mol Biol. 2018;1769:319-335. doi: 10.1007/978-1-4939-7780-2_20.
Chromothripsis is a phenomenon observed in cancer cells, wherein a single or few chromosome(s) exhibit vast genomic rearrangements. Recent studies elucidated a striking series of events in which defective segregation of chromosomes causes their incorporation into micronuclei, where they are subject to extensive DNA damage prior to re-joining the main mass of chromosomes in a subsequent cell cycle, which provide an appealing mechanism for the etiology of chromothripsis. Micronuclei are well known to be common in human preimplantation embryos. We recently showed that, unlike in cancer cells, in mouse preimplantation embryos the micronuclei are maintained during multiple cell generations and apparently fail to re-join the main set of chromosomes. This unexpected finding could safeguard the early embryonic genome from chromothripsis. Here, we describe an approach that combines live and immunofluorescence imaging methods that was pivotal in that study to reveal the lack of a functional kinetochore in chromosomes from mouse embryo micronuclei.
染色体碎裂是在癌细胞中观察到的一种现象，其中一条或少数几条染色体呈现出大量的基因组重排。最近的研究阐明了一系列惊人的事件，即染色体的分离缺陷导致它们被纳入微核，在随后的细胞周期中重新加入染色体主体之前，它们在微核中会受到广泛的DNA损伤，这为染色体碎裂的病因提供了一种有吸引力的机制。众所周知，微核在人类植入前胚胎中很常见。我们最近发现，与癌细胞不同，在小鼠植入前胚胎中，微核在多个细胞世代中得以维持，并且显然未能重新加入主要的染色体组。这一意外发现可能使早期胚胎基因组免受染色体碎裂的影响。在这里，我们描述了一种结合活细胞成像和免疫荧光成像方法的途径，该方法在该研究中至关重要，以揭示小鼠胚胎微核染色体中缺乏功能性动粒。
