AUTOSOMAL MECHANISMS OF TESTIS INDUCTION

睾丸诱导的常染色体机制

• 批准号: 6321292
• 负责人: VICKI N MEYERS-WALLEN
• 金额: $ 28.62万
• 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/6321292
• 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; 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：（从申请人的摘要中扫描）基因的识别 睾丸的确定途径增加了我们对 该决策途径的复杂性，并提供了分子诊断和 预防影响性发展的遗传疾病。 Sry是 被认为是编码哺乳动物睾丸确定因子的基因 直接受SRY影响的基因尚不清楚。这样的基因可能是负责的 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染色体的个体的发展。这不太可能 这些基因将在人类中被鉴定，因为小家族大小和 遗传异质性是连锁分析的严重障碍。动物模型 缺乏这些缺点，并提供了研究分子事件的手段 胚胎组织。性别确定预计在欧地人中会相似 哺乳动物和所有哺乳动物共有的步骤应适用于人类。 犬模型中的Sry阴性XX性逆转被遗传为常染色体 隐性特征。受影响的个体有雌性核型（78，xx）和 睾丸（XX雄性）或卵形（XX True Hermaphrodites）。犬 综合征与人类中的家族性Sry阴性XXSR非常相似， XX男性和XX True Hermaphrodites作为完整的兄弟姐妹出现。遗传 在这两个物种中，病因都是尚不清楚的。睾丸诱导的表征 在缺乏SIY的情况下机制将大大增加我们对 睾丸在分子水平上诱导。我们的长期目标是剖析 睾丸测定途径，通过表征具有睾丸诱导的基因 角色并解释其作用的分子机制。具体目标 该建议的内容是：（1）确定负责犬的常染色体基因 通过链接分析和筛选BAC库，SRY阴性XXSR。 （2） 比较受影响的胚胎和对照的性腺中的基因表达模式 在睾丸测定的正常时期（D28-32）。 （3）比较基因 正常后，受影响的胚胎和对照的性腺中的表达模式 睾丸测定期（D32-40）。对于目标2和3，我们将使用 定量逆转录酶聚合酶链反应和整个安装 比较Sox9，mis/amh的胚胎性腺表达的原位杂交 SF1，DAXL，WT-1和SRY。在此赠款期结束时，我们将拥有 鉴定了引起这种疾病的基因和睾丸途径的步骤 这是由于基因的时间，数量或位置的突变改变了 表达。