Identifying Novel Sex Determination Genes that protect from B6-YPOS Sex Reversal

鉴定可防止 B6-YPOS 性别逆转的新型性别决定基因

• 批准号: 8062352
• 负责人: Valerie A Arboleda
• 金额: $ 3.34万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8062352
• 关键词: 10q; 46,XY Gonadal Dysgenesis; Accounting; Adult; Alleles; Animals; Bioinformatics; Biological Assay; Breeding; Candidate Disease Gene; Chromosomes, Human, Pair 11; Classification; Congenic Strain; Development; Diagnosis; Diagnostic Procedure; Disease; Embryo; Embryonic Development; Female; Fluorescent in Situ Hybridization; Gene Expression; Gene Proteins; Genes; Genetic; Genetic Predisposition to Disease; Genital system; Genitourinary system; Goals; Gonadal structure; Human; Hypospadias; Live Birth; Molecular; Morphology; Mouse Strains; Mus musculus domesticus; Mutation; Nature; Organ Culture Techniques; Ovary; Patients; Phenotype; Physiological; Prevalence; Process; Role; SNP genotyping; Safe Sex; Testis; Y Chromosome; congenic; density; gene function; improved; in utero; in vitro Assay; interest; mRNA Expression; male; mature animal; mouse model; novel; protective effect; protein expression; research study; sex; sex determination; sex development disorder; sry Genes

DESCRIPTION (provided by applicant): Disorders of sex development (DSD) encompass a wide range of urogenital anomalies, ranging from mild hypospadias to sex reversal with genital ambiguity. Impressively, these disorders occur in approximately 0.5-1% of live births. Despite the prevalence of these disorders, the molecular mechanisms behind the transformation of the bipotential gonad into a testis or an ovary are not completely understood. Genetic studies of 46, XX or 46, XY sex reversal patients determined that mutations in either SRY or Steoidogenic Factor-1 (SF1) account for 30% of all isolated 46, XY Gonadal Dysgenesis (GD) where SRY is present by FISH analysis. Other rare and isolated causes of 46, XY GD include mutations in Chromobox-2 (CBX2), deletions in 9p or 10q, and duplications of SOX9. However, these genes account for less than 1% of all cases. This implies that there exist many undiscovered genes that are important in the developing mammalian gonad. In this proposal, we seek to better understand the molecular mechanisms behind mammalian sex determination using a powerful mouse model of C57BL/6J-YPOS sex reversal. The presence of the Mus domesticus poschiavinus Y chromosome, YPOS on the C57BL/6J (B6) genetic background causes 60% of B6- YPOS animals to be sex reversed, developing as adult females (2 ovaries) or hermaphrodites (1 ovary, 1 testis). B6-YPOS sex reversal occurs early in embryonic development, as all E15.5 animals develop some degree of ovotestis. We have developed a congenic strain in which a novel locus of 129-origin on chromosome 11 confers significant protection from B6-YPOS sex reversal. In this proposal, we will narrow the size of the congenic region on chromosome 11 to a manageable size for further study. To date, we have created 10 subcongenic lines, each containing a subset of the original congenic line, and preliminary studies in adult XY animals have identified a subcongenic line in which a small region of 1.3 Mb is sufficient to confer the protection phenotype. Using bioinformatics and mRNA and protein expression studies, we will investigate a small number of candidate genes in our 1.3 Mb region. The function of the top three candidate genes in sex determination will be assayed using gonadal organ culture. The third aim will focus on a complementary and independent approach to investigate the functional role of the congenic region, rather than a specific gene, to understand the mechanism behind the congenic regions' protective effect in early gonadal development. What we gain from this newfound understanding of sex determination will ultimately allow for better diagnosis and management of patients with disorders of sex development. PUBLIC HEALTH RELEVANCE: In this proposal, we investigate the molecular and cellular mechanisms that define the decision of the bipotential gonad to become a testis or an ovary; a process which is triggered by the expression of a male- specific gene, Sry, on the Y-chromosome. As only 25% of human cases of XY-sex reversal are explained genetically, we propose to identify new genes involved in this process using a mouse model of XY-sex reversal. This proposal will elucidate basic questions about how males and females diverge, beginning at gonadal development in utero, and will improve genetic classification and diagnostic methods of patients born with disorders of sex development.

描述（由申请人提供）：性发育障碍（DSD）包括范围广泛的泌尿生殖器异常，从轻度尿道下裂到伴有生殖器模糊的性反转。令人印象深刻的是，这些疾病发生在约0.5-1%的活产婴儿中。尽管这些疾病普遍存在，但双势性腺转化为睾丸或卵巢的分子机制尚不完全清楚。对46，xx或46，xy性逆转患者的遗传学研究确定，SRY或甾体生成因子-1 （SF1）突变占所有分离的46，xy性腺发育不良（GD）的30%，其中SRY存在FISH分析。其他罕见和孤立的原因包括染色体盒2 （CBX2）突变，9p或10q缺失，以及SOX9的重复。然而，这些基因只占所有病例的不到1%。这表明在哺乳动物性腺发育过程中存在许多未被发现的重要基因。在本研究中，我们试图通过C57BL/6J-YPOS小鼠性别逆转模型来更好地理解哺乳动物性别决定背后的分子机制。C57BL/6J （B6）遗传背景上的家鼠Y染色体YPOS的存在导致60%的B6- YPOS动物性别反转，发育为成年雌性（2个卵巢）或雌雄同体（1个卵巢，1个睾丸）。B6-YPOS性别逆转发生在胚胎发育早期，因为所有E15.5动物都有一定程度的卵睾丸。我们已经开发了一个同源菌株，其中11号染色体上的一个新的129起源位点对B6-YPOS性别逆转具有显著的保护作用。在这个建议中，我们将缩小11号染色体上的基因区域的大小到一个可控的大小，以供进一步的研究。到目前为止，我们已经创建了10个亚基因系，每个亚基因系包含原始基因系的一个子集，并且在成年XY动物中进行的初步研究已经确定了一个亚基因系，其中1.3 Mb的小区域足以赋予保护表型。利用生物信息学、mRNA和蛋白表达研究，我们将研究1.3 Mb区域的少量候选基因。性腺器官培养将检测在性别决定中排名前三的候选基因的功能。第三个目标将集中在互补和独立的方法来研究基因区域的功能作用，而不是一个特定的基因，以了解基因区域在早期性腺发育中的保护作用背后的机制。我们从对性别决定的新认识中获得的成果，最终将有助于更好地诊断和治疗性发育障碍患者。

项目成果

DSDs: genetics, underlying pathologies and psychosexual differentiation.

• DOI: 10.1038/nrendo.2014.130
• 发表时间: 2014-10
• 期刊: Nature reviews. Endocrinology