Germline Utx mutation as a model for transgenerational epigenetic inheritance

项目摘要 雄性配子将父亲的基因组传递给下一代。与此同时，他们还携带 受精时传递给合子的表观遗传信息。一个尚未回答的主要问题是， 遗传的表观遗传信息影响后代的基因表达、表型和疾病易感性。 我们发现，敲除小鼠雄性生殖系中的染色质调节基因Utx， 降低后代的存活率和增加肿瘤形成率，即使后代本身没有 携带Utx突变该提议将检验雄性生殖细胞中Utx的缺失诱导 配子中的表观遗传变化，在受精后改变基因表达，并最终导致 在后代中观察到肿瘤易感性增加。具体来说，这里提出的实验将检查 在发育和生长过程中组蛋白修饰、DNA甲基化和基因表达的全基因组变化， Utx条件性敲除的成熟雄配子（目的1）;评估基因表达和表型效应 在植入前和围产期阶段的下一代胚胎中的变化（目标2）;并确定 后代发育和成熟生殖细胞中组蛋白修饰、DNA甲基化和基因表达 以确定这些变化是否可以跨多代持续（目标3）。 本研究的最终目的是了解在发育和基因调控状态的变化， 哺乳动物雄性生殖细胞可以影响后代的表型和疾病。在过去，这个问题 主要通过使用化学或营养暴露来操纵父亲的环境来解决， 这是难以精确控制的。相比之下，本研究将采用一个简单，定义明确，高度 可用于产生生殖系表观遗传变化的可重复遗传操作。拟议 实验将阐明一种新的机制，通过这种机制，雄性配子中的表观遗传失调可以促进 男性不育症，这是NICHD的优先领域。研究结果还将为非遗传性疾病的发生建立一个新的机制。 疾病易感性的遗传，对常见的病原学和流行病学具有广泛的影响， 癌症和糖尿病等疾病。

PROJECT SUMMARY Male gametes transmit the paternal genome to the next generation. At the same time, they also carry epigenetic information that is passed to the zygote at fertilization. A major unanswered question is whether this inherited epigenetic information influences gene expression, phenotype, and disease susceptibility in offspring. We have found that knocking out the chromatin regulator gene Utx in the mouse male germ line leads to reduced survival and increased rates of tumor formation in offspring, even when offspring do not themselves carry a Utx mutation. This proposal will test the hypothesis that loss of Utx in male germ cells induces epigenetic changes in the gametes that alter gene expression after fertilization and ultimately result in the increased tumor susceptibility observed in offspring. Specifically, the experiments proposed here will examine genome-wide changes in histone modification, DNA methylation, and gene expression in developing and mature male gametes of Utx conditional knockouts (Aim 1); evaluate gene expression and phenotypic effects in embryos of the next generation at the preimplantation and perinatal stages (Aim 2); and define changes in histone modification, DNA methylation, and gene expression in developing and mature germ cells of offspring in order to determine if these changes can persist across multiple generations (Aim 3). The ultimate goal of this study is to understand how changes in the development and gene regulatory state of mammalian male germ cells can impact phenotype and disease in progeny. In the past, this question has been addressed primarily by manipulating the paternal environment using chemical or nutritional exposures, which are difficult to control precisely. In contrast, this study will employ a simple, well-defined and highly reproducible genetic manipulation that can be used to generate germline epigenetic changes. The proposed experiments will elucidate a new mechanism by which epigenetic misregulation in male gametes can contribute to male infertility, a priority area for NICHD. The results will also frame a new mechanism for non-genetic inheritance of disease susceptibility, with broad implications for the etiology and epidemiology of common diseases such as cancer and diabetes.