Biological mechanisms that eliminate aneuploid cells from a mosaic conceptus in the mouse model system

项目摘要 许多妇女与不孕症作斗争，只有大约30%的怀孕进展到活产， 其余通过自然流产失败，其中大多数与 非整倍性在这里，我们使用嵌合体非整倍体小鼠模型来研究染色体的影响， 在着床前、围着床期和着床后早期阶段，孕体发育的镶嵌现象。 我们先前已经表明，非整倍体的结果在不同的邻近组织中有两种不同的反应 植入前胚胎：胚胎外滋养外胚层的细胞周期延迟， 胎盘和细胞凋亡的内部细胞团，将建立胎儿。我们现在将决定 大多数非整倍体细胞持续到植入阶段的命运，以及在许多情况下， 这些可以在不损害植入形态发生和相关的 多能性状态的转变。我们将确定胚胎能够补偿的程度 以确保发育，并确定不同的细胞所采用的机制。 植入后组织，以科普非整倍体和保护多能谱系，产生所有 胚层和生殖系。对不同生物的研究表明，全球基因表达和 翻译水平与非整倍体的程度相关，我们将确定在非整倍体中是否存在非整倍体。 胚胎导致蛋白质组不平衡，导致一组常见的蛋白毒性应激反应， 诱导自噬。我们将阐明自噬在消除非整倍体细胞中的作用， 胚胎，并确定p53和mTOR在这一过程中的作用。我们的研究将揭示 非整倍体和二倍体细胞在发育过程中的竞争，并将揭示新的途径， 调节胚胎的生长和可塑性。它将通过建立一个有效的 了解被诊断为嵌合体的人类胚胎应该或不应该被 丢弃。这将有助于更准确地评估马赛克的发展潜力 非整倍体胚胎，并允许开发更好的方法来评估成功的可能性 怀孕

Project Summary Many women struggle with infertility with only around 30% of pregnancies progressing to live birth and the remainder failing through spontaneous abortions, the majority of which are associated with aneuploidy. Here we use a mouse model for mosaic aneuploidy to study the effects of chromosome mosaicism on development of the conceptus through the pre-, peri-and early post-implantation stages. We have previously shown that aneuploidy results in two different responses in different adjacent tissues of the pre-implantation embryo: cell cycle delay in the extra-embryonic trophectoderm that will establish the placenta and apoptosis in the inner cell mass that will establish the foetus. We will now determine the fate of the majority of aneuploid cells that persist into implantation stages and how, in many cases, these can be eliminated without compromising implantation morphogenesis and the associated transition in the state of pluripotency. We will determine the extent to which the embryo can compensate for lost aneuploid cells to ensure development and determine the mechanisms employed by different post-implantation tissues to cope with aneuploidy and protect the pluripotent lineage that generates all germ layers and germline. As studies in diverse organisms indicate that global gene expression and translation levels correlate with the degree of aneuploidy, we will determine whether aneuploidy in the embryo results in proteomic imbalance leading to a common set of proteotoxic stress responses that induce autophagy. We will elucidate the role of autophagy in the elimination of aneuploid cells from the embryo and determine the roles of p53 and mTOR in this process. Our study will shed light onto competition between aneuploid and diploid cells in development and will uncover new pathways that regulate embryo growth and plasticity. It will inform IVF strategies in the clinic by building a working knowledge of circumstances in which human embryos diagnosed as mosaic should or should not be discarded. It will enable a more accurate assessment of the developmental potential of mosaic aneuploid embryos and permit the development of better methods to assess the probability of successful pregnancy.