Characterization of aneuploidy, cell fate and mosaicism in early development

项目总结 胚胎中存在非整倍体(染色体异常)被认为是主要限制因素之一。 导致人类生殖成功和妊娠失败的重要原因，约占50% 早产的病症。在体外受精的人类胚胎中，非整倍体率高得惊人，约为60% 这些胚胎中有镶嵌的，既有非整倍体细胞，也有正常的整倍体细胞。频频发生的 马赛克现象在自然受孕和试管受精中都存在。然而，尽管发病率很高， 人类胚胎中的非整倍体及其分子机制和发育命运的认识 由于与人类胚胎和胎儿研究相关的相当大的伦理限制，细胞受到限制。 我以前的工作使用体外培养技术证明了非整倍体在早期分化中的谱系特异性行为。 人胚胎干细胞模型。为了进一步研究非整倍体的细胞生理学 植入，需要活体动物模型。普通的绒猴表现出自然产生的非整倍体， 使它们成为比啮齿动物更具代表性的人类模型。因此，我提出了一个绒猴模型 进一步剖析非整倍体细胞的命运及其在早期发育过程中的分子和细胞后果。我的 初步研究发现非整倍体绒猴胚胎干细胞优先分化 对BMP4刺激的反应，类似于我在hESCs中观察到的行为 我之前的工作表明，非整倍体在将干细胞限制在胚外命运中起到了保守的作用。 在训练期间，我将使用一种独特的绒毛干细胞模型(原肠)，它可以在早期重现 谱系指定和原肠形成研究BMP4信号在表型表现中的作用 非整倍体(目标1)。为了进一步研究非整倍体的消除和分配，我将构建嵌合体 应用绒猴胚胎探讨非整倍体细胞在植入前后胚胎中的命运和行为 体外发育(目标2)。由于我的初步数据显示，人类对非整倍体的容忍度更高 胚胎外血统，在获奖期的独立阶段，我建议分析基因 非整倍体在绒猴胎盘中的表达 胚外组织生理学。此外，在这个阶段，我将构建一个胎盘/滋养层细胞 CJ-ESCs中的有机类物质，以进一步剖析不同胎盘谱系中非整倍体的行为(目标3)。 综上所述，拟议的研究将提供一个全面的模型来研究以前没有特征的 胚胎发育过程中消除非整倍体的机制，为翻译 辅助生殖技术的应用。拟议中的项目也将成为我的一个平台 获得分子生物学和发育生物学、动物生殖科学、 和计算基因组学，这将对我作为一个独立的 生殖生物学领域的研究人员。

PROJECT SUMMARY The presence of aneuploidy (chromosomal abnormalities) in embryos is considered one of the major limitations to successful human reproduction and a significant cause of gestation failure, accounting for approximately 50% of early miscarriages. Aneuploidy rates are strikingly high in in vitro fertilized human embryos, and around 60% of these embryos are mosaic, containing both aneuploid and normal euploid cells. The frequent occurrence of mosaicism exists in both naturally conceived and IVF pregnancies. However, despite the high incidence of aneuploidy in human embryos, our knowledge of the molecular mechanisms and developmental fate of these cells is restricted due to the considerable ethical limitations associated with human embryo and fetal research. My previous work demonstrated lineage-specific behavior of aneuploidy in early differentiation using an in vitro human embryonic stem cell (hESC) model. To further characterize the cellular physiology of aneuploidy after implantation, an in vivo animal model is required. Common marmosets exhibit naturally occurring aneuploidy, making them a more representative model for humans than rodents are. Therefore, I propose a marmoset model to further dissect aneuploidy cell fate and its molecular and cellular consequences during early development. My preliminary data uncovered that aneuploid marmoset embryonic stem cells (cj-ESCs) preferentially differentiate into trophectoderm lineages in response to BMP4 stimulation, similar to the behavior I observed with hESCs in my previous work, suggesting a conserved role of aneuploidy in restricting stem cells to extraembryonic fates. During the training period, I will use a unique marmoset stem cell model (gastruloid) that recapitulates early lineage specification and gastrulation to investigate the role of BMP4 signaling in the phenotypic manifestation of aneuploidy (Aim 1). To further investigate the elimination and allocation of aneuploidy, I will construct mosaic marmoset embryos to probe aneuploidy cell fate and behaviors during pre-and post-implantation embryonic development in vitro (Aim 2). Since my preliminary data indicates a higher tolerance of aneuploidy in the extraembryonic lineages, during the independent phase of the award period, I propose to analyze the gene expression profile of aneuploidy in the marmoset placenta to understand the effects of aneuploidy on the cellular physiology of extraembryonic tissue. In addition, during this phase, I will construct a placental/trophoblast organoid from cj-ESCs to further dissect the behaviors of aneuploidy in different placental lineages (Aim 3). Together, the proposed research will present a comprehensive model for studying a previously uncharacterized mechanism underlying the elimination of aneuploidy during embryogenesis, paving the way for translational applications to assisted reproductive technologies. The proposed project will also serve as a platform for me to obtain training and scientific expertise in molecular and developmental biology, animal reproductive sciences, and computational genomics which will contribute significantly to my career development as an independent investigator in the field of reproductive biology.