Germline transmission of epigenetic alterations to offspring

摘要：本研究的总体目标是阐明生殖细胞在人类生殖系统中的作用， 表观遗传改变（表观突变）的发生和发展的代际和跨代 生殖缺陷到目前为止，已发表的科学文献表明， 表观遗传改变，主要是DNA甲基化、组蛋白修饰和RNA修饰 （表转录组），通过生殖系（卵子或精子）传递给后代1。 然而，观察到的表型突变在生殖表型发育中的作用并不重要。 由于缺乏对PGC对生殖系和生殖系-生殖系的清晰理解， 世代更替过程中重编程抗性表型突变的索马转移。这里 在拟议的研究中，我们提出了三个大问题：a）生殖系表型突变是否建立了 年龄和发育阶段，特别是男性？B）是否有祖先 跨代表型突变使后代易于增加生殖风险， 如果再次暴露于新出现的令人担忧的环境化学品，是否会造成损害？（三）作用 在表型性状进展的发展中观察到的表型突变导致或 相关的？这个R 01研究项目将系统地回答这些问题，在三个不同的 目标。BPA将被用作普遍存在的内分泌干扰化学品（EDC）模型， 双酚S（BPS）将被用作一种新出现的令人担忧的污染物，青鳉鱼将被用作 比较脊椎动物模型。目标1将检验男性生殖细胞 发展阶段容易受到BPA，模型EDC。目标2将检验以下假设： 预先存在表突变的F3代后代暴露于新出现的污染物 会导致生殖障碍的发生率增加。目标3将检验假设 EDC诱导的表突变与男性和女性生育力降低有关， 这些表观突变可以通过可重编程的CRISPR-dCas 9表观基因组编辑来纠正， in vivo.该项目将确定过去暴露的足迹，确定 表型突变在生殖障碍，确定是否遗传表型突变易患 今世后代生殖健康风险增加的风险， 新出现的污染物的关注，并提供了重要的见解机制， 表观基因组的生殖系传播和暴露的纵向健康风险。理解 关键的时间点，在此期间，表位突变转移将提供洞察战略， 减轻未来雌激素化学品对人类生殖健康的影响。

ABSTRACT: The overall goal of this research program is to delineate the role of germline epigenetic alterations (epimutations) in the onset and progression of inter-and transgenerational reproductive defects. So far, published scientific literature suggests that environmentally induced epigenetic alterations, mainly DNA methylation, histone modifications, and RNA modifications (epitranscriptome), are transmitted to subsequent generations via germline (eggs or sperm)1. However, the role of observed epimutations in the development of reproductive phenotypes is not well understood because of a lack of clear understanding of PGC to germline and germline-to soma transfer of reprogramming-resistant epimutations during the turnover of generations. Here in the proposed study, we are asking three big questions: a) Do germline epimutations establish age and developmental stage specifically in males? b) Do ancestrally established transgenerational epimutations predispose future generations to increased risks for reproductive impairment if exposed again to emerging environmental chemicals of concern? c) Is the role of the observed epimutations in the development of progression of phenotypic traits causative or correlative? This R01 research project will systematically answer these questions in three different aims. BPA will be used as a ubiquitous model endocrine-disrupting chemical (EDC), and Bisphenol S (BPS) will be used as an emerging contaminant of concern, and medaka fish as a comparative vertebrate animal model. Aim 1 will test the hypothesis that male germ cells at all stages of development are susceptible to BPA, the model EDC. Aim 2 will test the hypothesis that exposure of the F3 generation offspring with pre-existing epimutations to emerging contaminants will result in an increased incidence of reproductive impairment. Aim 3 will test the hypothesis that the EDC-induced epimutations are associated with reduced fertility in males and females and that these epimutations can be corrected by reprogrammable CRISPR-dCas9 epigenome editing in vivo. The project will identify footprints of the past exposure, determine the role of epimutations in reproductive impairment, determine whether inherited epimutations predispose current and future generations to increased risks of reproductive health due to exposure to emerging contaminants of concern, and provide significant insights into mechanisms underlying germline transmission of the epigenome and longitudinal health risks of exposure. Understanding of key time points during which epimutations transfer would provide insights into strategies for the mitigation of future estrogenic chemical-induced reproductive health effects in humans.