A Novel Gene Required for Sertoli-Spermatids Adhesion

支持精细胞粘附所需的新基因

• 批准号: 6831202
• 负责人: GRANT R MACGREGOR
• 金额: $ 25.55万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-12-01 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6831202
• 关键词: Sertoli cells; cell adhesion; cell cycle; cell transplantation; clinical research; cytogenetics; fertility; gene expression; gene induction /repression; genetically modified animals; immunocytochemistry; in situ hybridization; laboratory mouse; male; nondrug contraceptive; northern blottings; site directed mutagenesis; sperm; spermatogenesis; yeast two hybrid system

DESCRIPTION (provided by applicant): Each year, over 1 million abortions are performed in the US as a consequence of unintended pregnancy. Unintended pregnancies therefore have a significant negative impact on both the individual and society. Contraception is an effective method of reducing unintended pregnancies. One way to further reduce the rate of unintended pregnancies is to develop safe and effective methods for reversible male contraception. Hormone based approaches have been developed for use in men. However, these can have significant side effects including the length of time required for both contraception and its reversal. In theory, a specific inhibitor of spermiogenesis could be a powerful contraceptive method, as it should take effect, and be reversed, relatively quickly. Thus, a challenge for basic research is to improve our understanding of the gene products and pathways required for spermiogenesis so that some of these discoveries may be translated into novel approaches for male contraception. Towards this goal, we have used random insertional mutagenesis in mice to identify genes required specifically for mammalian spermatogenesis. Homozygous symplastic spermatids (sys) male mice are sterile due to a defect in spermatid-Sertoli cell adhesion just prior to spermatid elongation. The sys mutation involves a deletion of 1.2 Mb of mouse chromosome 14 that appears to contain only one, novel gene. This gene is predicted to encode a membrane-anchored structural protein with a proline rich N-terminus. We hypothesize that a defect in this novel gene is responsible for the sterility in sys homozygote males, that this gene functions in the Sertoli cell to mediate spermatid-Sertoli adhesion, and that inhibition of the genes function in fertile adult male mice could block spermatid development. Five specific aims are proposed to test this hypothesis. First, we shall generate male mice with a specific mutation of the novel gene and verify that they are sterile. Second, we shall use germ cell transplantation to investigate whether the function of the novel gene is required in germ cells or somatic cells within the testes. Third, we shall analyze the expression pattern and subcellular distribution of the gene product in testes using RNA in situ hybridization, immunohistochemistry and biochemical methods. Fourth, we shall investigate how the gene product functions by identifying proteins that interact with it in the testes. Finally, we shall investigate whether inactivation of this gene in adult fertile male mice can block spermiogenesis. The results of this basic research will provide information about a new gene product whose function is required for spermatid-Sertoli adhesion. They will also provide an assessment of the suitability of this novel gene product as a potential target for development of new methods of male contraception.

描述（由申请人提供）：每年，美国有超过 100 万例因意外怀孕而进行的堕胎。因此，意外怀孕对个人和社会都会产生重大的负面影响。避孕是减少意外怀孕的有效方法。进一步降低意外怀孕率的一种方法是开发安全有效的可逆男性避孕方法。基于激素的方法已被开发用于男性。然而，这些可能会产生显着的副作用，包括避孕及其逆转所需的时间长度。理论上，精子发生的特定抑制剂可能是一种强大的避孕方法，因为它应该相对较快地生效和逆转。因此，基础研究的一个挑战是提高我们对精子发生所需的基因产物和途径的理解，以便其中一些发现可以转化为男性避孕的新方法。为了实现这一目标，我们在小鼠中使用随机插入诱变来鉴定哺乳动物精子发生所需的基因。纯合共体精子细胞 (sys) 雄性小鼠由于精子细胞伸长前精子细胞与支持细胞粘附缺陷而无法生育。 sys 突变涉及小鼠 14 号染色体 1.2 Mb 的缺失，该染色体似乎只包含一个新基因。该基因预计会编码具有富含脯氨酸的 N 末端的膜锚定结构蛋白。我们假设这个新基因的缺陷是导致 sys 纯合雄性不育的原因，该基因在支持细胞中发挥作用，介导精子细胞-支持细胞粘附，并且抑制该基因在可育成年雄性小鼠中的功能可能会阻碍精子细胞的发育。提出了五个具体目标来检验这一假设。首先，我们将产生具有新基因特定突变的雄性小鼠，并验证它们是不育的。其次，我们将利用生殖细胞移植来研究睾丸内的生殖细胞或体细胞是否需要新基因的功能。第三，利用RNA原位杂交、免疫组化和生化方法分析该基因产物在睾丸中的表达模式和亚细胞分布。第四，我们将通过鉴定睾丸中与其相互作用的蛋白质来研究基因产物如何发挥作用。最后，我们将研究成年可育雄性小鼠中该基因的失活是否会阻碍精子发生。这项基础研究的结果将提供有关一种新基因产物的信息，该基因产物的功能是精子细胞-支持细胞粘附所必需的。他们还将评估这种新型基因产物作为开发男性避孕新方法的潜在目标的适用性。