AUTOSOMAL MECHANISMS OF TESTIS INDUCTION

睾丸诱导的常染色体机制

• 批准号: 6711165
• 负责人: VICKI N MEYERS-WALLEN
• 金额: $ 25.04万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6711165
• 关键词: artificial chromosomes; autosomal recessive trait; biological models; cell differentiation; disease /disorder etiology; dogs; embryo /fetus; gene expression; genes; genetic library; histogenesis; in situ hybridization; linkage mapping; model design /development; molecular cloning; molecular genetics; molecular pathology; polymerase chain reaction; reproductive development; sex determination; testis

DESCRIPTION: (Scanned from the applicant's abstract) Identification of genes in the testis determination pathway has increased our understanding of the complexity of this decision pathway and provided molecular diagnosis and prevention for inherited disorders affecting sexual development. Sry is accepted as the gene encoding the testis-determining factor in mammals, yet genes directly affected by Sry are unknown. One such gene may be responsible for Sry-negative XX sex reversal, wherein an autosomal gene induces testis development in individuals lacking Sry and the Y chromosome. It is unlikely that these genes will be identified in humans because small family sizes and genetic heterogeneity are severe impediments to linkage analysis. Animal models lack these disadvantages and provide the means to study molecular events in embryonic tissue. Sex determination is expected to be similar among eutherian mammals, and steps common to all mammals should be applicable to humans. Sry-negative XX sex reversal in the canine model is inherited as an autosomal recessive trait. Affected individuals have a female karyotype (78,XX) and either testes (XX males) or ovotestes (XX true hermaphrodites). The canine syndrome is strikingly similar to familial Sry-negative XXSR in humans, in which XX males and XX true hermaphrodites occur as full siblings. The genetic etiology is unknown in both species. Characterization of the testis induction mechanism in the absence of Siy would greatly increase our understanding of testis induction at the molecular level. Our long term goal is to dissect the testis determination pathway, by characterizing genes having a testis induction role and explaining the molecular mechanism of their actions. The specific aims of this proposal are: (1) Identify the autosomal gene responsible for canine Sry-negative XXSR, through linkage analysis and screening a BAC library. (2) Compare the gene expression pattern in gonads of affected embryos and controls during the normal period of testis determination (d28-32). (3) Compare the gene expression pattern in gonads of affected embryos and controls after the normal period of testis determination (d32-40). For Aims 2 and 3 we will use quantitative reverse transcriptase polymerase chain reaction and whole mount in situ hybridization to compare embryonic gonadal expression of Sox9, MIS/AMh, Sf1, Daxl, Wt-1 and Sry. At the end of this grant period, we will have identified the gene causing this disorder and the step in the testis pathway that is altered by the mutation in timing, quantity, or location of gene expression.

描述：（从申请人摘要中扫描） 睾丸决定通路增加了我们对 这一决定途径的复杂性，并提供了分子诊断， 预防影响性发育的遗传性疾病。斯里群岛 被认为是哺乳动物睾丸决定因子的编码基因， 直接受Sry影响的基因是未知的。其中一个基因可能是 对于Sry阴性XX性逆转，其中常染色体基因诱导睾丸 缺乏Sry和Y染色体的个体的发育。可能性不大 这些基因将在人类中被发现，因为家庭规模小， 遗传异质性是连锁分析的严重障碍。动物模型 没有这些缺点，并提供了研究分子事件的手段， 胚胎组织性别决定预计是类似的真兽目 哺乳动物，所有哺乳动物共有的步骤应适用于人类。 Sry阴性XX性逆转犬模型是作为常染色体遗传 隐性性状受影响的个体具有女性核型（78，XX）， 睾丸（XX雄性）或卵睾丸（XX真雌雄同体）。犬 综合征与人类的家族性Sry阴性XXSR惊人相似， 其中XX个男性和XX个真两性人是完全的兄弟姐妹。遗传 这两个物种的病因尚不清楚。睾丸诱导的表征 在没有Siy的情况下的机制将大大增加我们对 睾丸诱导在分子水平上。我们的长期目标是解剖 睾丸决定途径，通过表征具有睾丸诱导的基因 的作用，并解释其作用的分子机制。具体目标 本研究的主要内容是：（1）确定犬的常染色体基因 Sry阴性的XXSR，通过连锁分析筛选出BAC文库。（二） 比较受影响胚胎和对照组性腺中的基因表达模式 睾丸测定正常期（d28-32）。(3)比较基因 正常发育后，受影响胚胎和对照组性腺中的表达模式 睾丸测定期（d32-40）。对于目标2和3，我们将使用 定量逆转录聚合酶链反应和整体封片 原位杂交比较胚胎性腺中Sox 9、MIS/AMh Sf 1、Daxl、Wt-1和Sry.在这段时间结束后，我们将 确定了导致这种疾病的基因和睾丸途径中的步骤 由基因的时间、数量或位置突变而改变的 表情