Cellular and Molecular Basis of Human Primordial Germ Cell Specification

摘要 人类生殖细胞对人类生殖是必不可少的，因为只有这些细胞才能分化 进入配子并将DNA从父母传给孩子。人类生殖系的先锋细胞开始 在胎儿时期形成的，在胚胎时期，少量的胚胎细胞被搁置 在被称为人类原始生殖细胞(HPGC)规范的过程中着床和原肠形成。这 人类生殖细胞发育中的关键事件对个人的未来产生巨大影响 生殖健康作为hPGC规范中的一项失败，会导致某些不孕症。在这场竞争性的更新中， 目的是增加我们对hPGC规范的细胞和分子基础的基础知识。基座 根据上一个资助期的实验结果，我们计划使用人类胚胎干细胞(HESCs)。 和人诱导多能干细胞(HPSCs)和hPGC样细胞(HPGCLCs)向 实现这一目标。总体假设是，非啮齿动物和人类特有的分子事件 进化以规范hPGC规范。鉴于这笔拨款的重点主要是基因组的区域 这是人类独有的，这个项目非常适合人类细胞模型的使用。在目标1中， 需要解决的假说是Tfap2c结合的人类特异性逆转座子调节hPGC 规格。在目标2中，要解决的假设是Tfap2c的表达受 在hPGCLC分化过程中，反转录转座子受表观基因组靶向改变的调控。在 第三个目标，我们将评估hPGC规范中Tfap2c和SOX17的关系，并使用 假设Tfap2c在家族启动的hPGC前体中作用于SOX17的上游以调节 HPGCs的规格。总而言之，这种竞争性更新建立在第一笔资金成功的基础上 为识别人类基因组中具有以下特征的新基因座贡献基本知识的时期 进化以调节hPGCs的规格和身份。

Summary Human germline cells are essential for human reproduction as only these cells are capable of differentiating into gametes and transmitting DNA from parent to child. The pioneering cells of the human germline begin to form during prenatal life when a small number of embryonic cells are set aside around the time of embryo implantation and gastrulation in a process known as human primordial germ cell (hPGC) specification. This critical event in human germline cell development has a tremendous impact on an individual's future reproductive health as a failure in hPGC specification causes certain infertility. In this competitive renewal, the goal is to increase our fundamental knowledge on the cell and molecular basis of hPGC specification. Based on experimental results in the previous funding period, we aim to use human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) and the differentiation of hPGC-like cells (hPGCLCs) to achieve this goal. The overall hypothesis is that non-rodent and human-specific molecular events have evolved to regulate hPGC specification. Given that the focus of this grant is largely on regions of the genome that are uniquely human, this project is perfectly suited to the use of human cell-based models. In aim 1, the hypothesis to be addressed is that TFAP2C-bound human-specific retrotransposons regulate hPGC specification. In aim 2, the hypothesis to be addressed is that the expression of TFAP2C bound retrotransposons are regulated by targeted changes to the epigenome during hPGCLC differentiation. In the third aim, we will evaluate the relationship between TFAP2C and SOX17 in hPGC specification, with the hypothesis that TFAP2C functions upstream of SOX17 in a lineage primed hPGC progenitor to regulate specification of hPGCs. In summary, this competitive renewal builds upon success from the first funding period to contribute essential knowledge on the identification of new loci in the human genome that have evolved to regulate the specification and identity of hPGCs.