Roles of X- and Y-palindromic Genes in Mammalian Fertility

项目摘要 哺乳动物的性染色体富含含有基因家族的大回文序列 几乎只在生精细胞中表达，然而这些回文基因的分子功能 基因在很大程度上仍不为人所知。理解个体回文基因的机制功能 家族将提供对导致生精缺陷(畸形)的遗传因素的新见解 在睾丸生殖细胞的发育中)。这项建议的目的是精确删除个别X- 和Y回文基因家族，以确定它们在精子发生过程中的分子功能。这项建议 解决了单个X回文或Y回文基因家族所有拷贝成员的缺失是否会导致 生精缺陷。这一命题是基于这样一种观察，即删除移除所有 X或Y回文基因家族导致生精缺陷。然而，这些都是以前研究过的 缺失移除了更多的基因，而不仅仅是单个回文基因家族，这使得确定它变得困难 单个回文基因家族对精子发生缺陷的贡献。因此，我们建议 产生精确的缺失，移除小鼠中单个X或Y回文基因家族的所有成员 了解它们在精子发生中的作用。作为可行性的证明，我们已经产生了两个独立的， SLX和SLXL1X回文基因家族百万碱基大小的缺失表明雄性小鼠携带 这两个基因家族的缺失都是不育的，表现出特定的减数分裂后生精缺陷(初步 研究)。这项建议通过两个具体目标解决了X和Y回文基因的重要性：1) 确定SLX和SLXL1X回文基因家族在男性减数分裂后精子发生中的作用 携带SLX和SLXL1回文序列缺失的小鼠；2)确定四个 精子发生中额外的X-和Y-回文基因家族 不同的基因家族。X-和Y-回文基因家族功能的遗传学分析 小鼠，我们已经开发出新的染色体工程方法来有效地删除大回文 活体内的区域。小鼠的每个X-和Y-回文基因家族将被系统地表征为 精子发生的缺陷。单个X-和Y-回文基因家族的功能一直很差 在人类和老鼠身上进行了研究，因为他们最近的发现和复杂的基因组结构。这个 拟议的实验将提供对X和Y回文个体作用的更好理解 男性生育能力的基因。事实上，X-和Y-回文包含睾丸特异的基因家族，这使得它们 是发现导致人类生精缺陷的新遗传因素的理想人选。通过 了解X和Y回文基因家族的分子功能可以获得重要的见解 它们在精子发生中的作用以及X和Y回文基因家族的突变如何破坏 精子发生。

Project Summary Mammalian sex chromosomes are enriched with large palindromic sequences harboring gene families expressed almost exclusively in spermatogenic cells, however the molecular functions of these palindromic genes remain largely unknown. Understanding the mechanistic functions of individual palindromic gene families will provide novel insights into genetic factors that contribute to spermatogenic defects (abnormalities in the development of testicular germ cells). The objective of this proposal is to precisely delete individual X- and Y-palindrome gene families to determine their molecular functions during spermatogenesis. This proposal addresses whether deletion of all copy members of an individual X- or Y-palindromic gene family results in spermatogenic defects. This proposition is based on the observation that deletions that remove all members of X- or Y-palindromic gene families result in spermatogenic defects. However, each of these previously studied deletions remove more genes than just an individual palindromic gene family, making it difficult to determine the contribution of individual palindromic gene families to spermatogenic defects. Therefore, we propose to generate precise deletions that remove all members of individual X- or Y-palindromic gene families in mice to understand their role in spermatogenesis. As proof of feasibility, we have generated two, independent, megabase-sized deletions of the Slx and Slxl1 X-palindromic gene families and show that male mice carrying deletions of both gene families are infertile, exhibiting a specific post-meiotic spermatogenic defect (Preliminary Studies). This proposal addresses the importance of X- and Y-palindromic genes via two specific aims: 1) Determine the role of the Slx and Slxl1 X-palindromic gene families in post-meiotic spermatogenesis in male mice carrying deletions of both the Slx and Slxl1 palindrome arrays; 2) Determine the contribution of four additional X- and Y-palindromic gene families in spermatogenesis by individually deleting each of the four distinct gene families. To genetically dissect the functions of individual X- and Y-palindromic gene families in mice, we have developed new chromosome engineering methodologies to efficiently delete large palindromic regions in vivo. Each of the X- and Y-palindromic gene families in mice will be systematically characterized for defects in spermatogenesis. The functions of individual X- and Y-palindromic gene families have been poorly studied in humans and mice because of their recent discovery and complex genomic architecture. The proposed experiments will provide an improved understanding of the roles of individual X- and Y-palindromic genes in male fertility. The fact that X- and Y-palindromes harbor testis-specific gene families makes them ideal candidates for uncovering new genetic factors responsible for human spermatogenic defects. By understanding the molecular functions of X- and Y-palindromic gene families, important insights can be gained into their role in enabling spermatogenesis and how mutations in X- and Y-palindromic gene families disrupt spermatogenesis.