Do we need Y chromosome for successful reproduction?

我们需要Y染色体才能成功繁殖吗？

基本信息

批准号：
9187054
负责人：
Monika A Ward
金额：
$ 1.95万
依托单位：
UNIVERSITY OF HAWAII AT MANOA
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-25 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9187054
关键词：
Abnormal Cell Activities of Daily Living Affect Assisted Reproductive Technology Bypass Chromatin Chromosome abnormality Chromosomes Chromosomes, Human, Y Complement DNA DNA Packaging Data Defect Development Fathers Fertility Fertilization Gene Delivery Gene Transfer Gene Transfer Techniques Genes Genetic Germ Germ Cells Goals Gonadal structure Haploidy Homologous Gene Human Infertility Injection of therapeutic agent Learning Life Link Maintenance Male Infertility Mediating Meiosis Modeling Mus Oocytes Personal Satisfaction Play Ploidies Population Process Production Regulation Reproduction Role Severities Sex Chromosomes Spermatids Spermatogenesis Testing Testis Transgenes Transgenic Mice Transgenic Organisms Translating Ultrasonography Y Chromosome Y chromosome deletion arm assisted reproduction gene function gene replacement in vivo male men mouse model novel offspring overexpression promoter sex determination sperm cell sperm function spermatogonial arrest sry Genes testis determining factor

项目摘要

DESCRIPTION (provided by applicant): Male infertility affects 5-10% of the population. A major factor associated with male infertility is Y chromosome deletions, yet our understanding of the requirement for specific genes on the Y chromosome and of their roles in sperm production/function is still poor. Y chromosome genes may provide essential spermatogenic functions or just potentiate the spermatogenic process. Our long-term goal is to define the function of Y chromosome encoded genes in mice in a context of assisted reproduction technologies (ART) as a way to model human Y- linked infertility cases. We have established that only two Y chromosome genes, testis determinant gene Sry and spermatogonial proliferation factor Eif2s3y are required for production of male gametes capable of participating in assisted fertilization. In Preliminary Data we show that males with a Y complement limited to Sry and Eif2s3y have spermatogenesis arrest and do not produce mature sperm. The precursor haploid germ cells (spermatids) are rare and often abnormal. Nevertheless, with round spermatid injection (ROSI) we succeeded in producing viable, healthy, and fertile progeny. This offers a promise to men with extensive Y gene loss and resulting azoospermia. Here, our specific goal is to define whether ART can be achieved even without this minimum Y gene contribution. We will test the hypothesis that the Y chromosome complement can be eliminated entirely while retaining production of functional male gametes. In Aim 1 we wil test if transgenic activation of Sox9, a downstream effector of Sry, will effectively replace Sry function and whether Sry-to-Sox9 replacement affects spermatogenesis and fertility, testing directly for the as yet unknown function of these genes in mature gonads. We will also establish if Eif2s3x, an X encoded homologue of Eif2s3y, can replace Eif2s3y function in spermatogonial proliferation. We will generate and characterize mice transgenic for Eif2s3x, and assess whether overexpression of Eif2s3x can rescue spermatogonial proliferation arrest in XOSry mice. In Aim 2, we will produce males without any Y genes but with overexpression of Eif2s3x and with transgenic activation of Sox9, as well as males with one Y gene retained and the other replaced. We will investigate how the presence of these genes affects spermatogenesis progression. We will also test if spermatogenesis in these males enables development of germ cells functional in ART, and whether such produced offspring are normal. In Aim 3, we will attempt to rescue spermatogonial arrest in testes of mature males with in vivo Eif2s3y gene transfer using novel 'active transgenesis' approach and ultrasound mediated gene delivery. Our studies will advance the understanding of (1) the roles that key players of sex determination (Sry and Sox9) play in mature gonads; (2) the roles of sex chromosome genes (Eif2s3y and Eif2s3x) in the initiation of spermatogenesis; and (3) the compatibility of extensive Y gene loss with successful ART. Our results should translate to enhance treatment of human infertility associated with Y chromosome deletions.

描述（由申请人提供）：男性不育症影响5-10％的人口。与男性不育症相关的一个主要因素是Y染色体缺失，但是我们对Y染色体特定基因的需求及其在精子生产/功能中的作用仍然很差。 Y染色体基因可能提供必不可少的精子功能，或者只是增强了精子生成过程。我们的长期目标是在辅助生殖技术（ART）的背景下定义小鼠中Y染色体编码基因的功能，以建模人类Y连接的不育病例。我们已经确定，只有两个Y染色体基因，睾丸决定词基因SRY和精子增生因子EIF2S3Y才能产生能够参与辅助施肥的雄性配子。在初步数据中，我们表明，与SRY和EIF2S3Y相互补充的男性具有精子发生停滞，并且不会产生成熟的精子。前体单倍生殖细胞（精子）很少见，通常异常。然而，随着精子注射（ROSI），我们成功地产生了可行，健康和肥沃的后代。这为具有广泛基因损失和导致的无植物的男性提供了希望。在这里，我们的具体目标是确定即使没有这种最低基因的贡献，是否可以实现艺术。我们将检验以下假设：Y染色体补体可以在保留功能性男配子的产生时完全消除。在AIM 1中，我们将测试SOX9的转基因激活（SRY的下游效应子）将有效地替代SRY功能，以及SRY到SOX9的替代是否会影响精子发生和生育能力，直接测试这些基因在成熟的性别性别中尚未知道的功能。我们还将确定EIF2S3X是EIF2S3Y的X编码同源物，是否可以替换精子增生中的EIF2S3Y功能。我们将生成和表征EIF2S3X的小鼠转基因，并评估EIF2S3X的过表达是否可以挽救Xosry小鼠中的精子性增生。在AIM 2中，我们将产生没有任何Y基因的雄性，但具有EIF2S3X的过表达以及Sox9的转基因激活，以及一个Y基因保留的雄性，另一个替代了。我们将研究这些基因的存在如何影响精子发生进展。我们还将测试这些雄性中的精子发生是否使生殖细胞在ART中起作用，以及产生的后代是否正常。在AIM 3中，我们将尝试使用新型的“活性转基因”方法和超声介导的基因递送在体内EIF2S3Y基因转移的成熟雄性中挽救精子停滞。我们的研究将促进对（1）性别决定者（SRY和SOX9）在成熟的性腺中发挥的关键人物的理解；（2）性别染色体基因（EIF2S3Y和EIF2S3X）在精子发生启动中的作用；（3）广泛的基因丧失与成功的艺术的兼容性。我们的结果应转化为增强与Y染色体缺失相关的人类不育症的治疗。