Impact of 3' untranslated region sequence variants in spermiogenic gene expression and infertility

男性不育症是公认的主要健康问题在美国。临床上，主要原因是 精液质量差，即少精子症、弱精子症和/或畸形精子症。的一半左右 不孕症被认为是遗传性的，尽管分子基础大多是未知的。 值得注意的是，这些精子缺陷并不局限于不育男性;约2%的男性表现出次优精子 许多发达国家的男性精子数量在2008年减少了一半以上， 过去40年。同样，根本原因不明。因此，了解分子生物学是一个优先事项。 这些令人不安的男性生殖问题增加的基础。关于遗传和表观遗传 不孕症的贡献，有许多阶段和分子过程，可以受到影响，包括所有 精子发生的各个阶段，以及生育所需的数千个基因的作用。该项目的重点是后- 精子发生过程中的转录基因调控，圆形单倍体 精子细胞经历戏剧性的形态发育，成为成熟的，有鞭毛的精子， 高度紧凑的惰性基因组转录后基因调控在人类基因组中起着重要的作用。 精子发生3′UTR（3′非翻译区）在这方面是中心，影响mRNA的稳定性， 通过影响多聚腺苷酸化，进入调节蛋白和非编码RNA， 并装载到核糖体或核糖核蛋白颗粒（RNP）上。该项目旨在了解如果和 不育患者3′ UTR的变异/突变如何在单倍体基因表达和不育中发挥作用。 目的确定转录后调节功能是否存在系统性或特异性改变 使用从精液中纯化的圆形精子细胞的3′RNA-seq， 公共基因组序列数据。基于这些数据，我们将识别并优先考虑存在于 生物信息学预测的影响mRNA稳定性或其他相关属性的基序，侧重于基因 与精子生成有关在Aim II中，候选变体将通过高通量体外 系统来识别那些确实对mRNA稳定性和/或翻译有影响的物质。最后，Aim III将 创建这些假定致病变异的小鼠模型，并评估分子和表型效应 对生殖参数如精子数量、形态、活力和生育力的影响。总的来说，如果成功， 这将是迄今为止最大的努力，以确定遗传病变，导致不孕症，通过破坏后， 转录基因表达

Male infertility is well-recognized as a major health problem in the United States. Clinically, the major cause is poor semen quality, that is, oligozoospermia, asthenozoospermia, and/or teratozoospermia. About half of infertility cases are thought to be genetic in nature, although the molecular bases are mostly unknown. Remarkably, these sperm defects are not limited to infertile men; ~2% of all men exhibit suboptimal sperm parameters, and the sperm counts among men in many developed countries have more than halved in the past 40 years. Again, the underlying causes are unknown. Thus, it is a priority to understand the molecular basis of these disturbing increases in reproductive problems in men. With respect to genetic and epigenetic contributions to infertility, there are many stages and molecular processes that can be affected, including all stages of spermatogenesis, and roles for thousands of genes required for fertility. This project focuses on post- transcriptional gene regulation during spermiogenesis, the elaborate process by which round haploid spermatids undergo dramatic morphological development to become mature, flagellated spermatozoa with a highly compacted, inert genome. Post-transcriptional gene regulation plays a substantial role in spermiogenesis. The 3′UTR (3′ untranslated region) is central in this respect, affecting mRNA stability, translation and localization by influencing polyadenylation, access to regulatory proteins and noncoding RNAs, and loading onto ribosomes or ribonuclear protein particles (RNPs). This project seeks to understand if and how variation/mutation in the 3′UTRs of infertility patients plays a role in haploid gene expression and infertility. Aim I will determine if there are systematic or specific alterations in the post-transcriptional regulatory function of 3′UTRs in fertile versus infertile men, using 3′RNA-seq of round spermatids purified from ejaculates, and public genome sequence data. Based on these data, we will identify and prioritize variants that reside within motifs predicted bioinformatically to impact mRNA stability or other relevant attributes, focusing on genes implicated in spermiogenesis. In Aim II, candidate variants will be screened via a high-throughput in vitro system to identify those that indeed have an impact on mRNA stability and/or translation. Finally, Aim III will create mouse models of these putative pathogenic variants, and assess molecular and phenotypic effects upon reproductive parameters such as sperm number, morphology, motility, and fertility. Overall, if successful, this will be the largest effort to date to identify genetic lesions that cause infertility via disruption of post- transcriptional gene expression.