Molecular Genetics of X-linked Cataracts

X连锁白内障的分子遗传学

• 批准号: 7495869
• 负责人: KRISTEN M HUANG
• 金额: $ 10.7万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7495869
• 关键词: Affect; Amino Acids; Animal Model; Attention; Backcrossings; Bacterial Artificial Chromosomes; Bacterial Chromosomes; Biochemical Genetics; Birth; Candidate Disease Gene; Cataract; Complement; Complementary DNA; Contig Mapping; DNA Sequence; Databases; Defect; Dental; Development; Disease; Disruption; Etiology; Event; Expressed Sequence Tags; Female; Ganciclovir; Gene Targeting; Generations; Genes; Genetic Recombination; Genetic Transcription; Genomic Library; Homologous Gene; Human; Human Genome; Implant; Individual; Knockout Mice; Length; Libraries; Link; Location; Maps; Metacarpal bone; Molecular; Molecular Genetics; Mus; Mutate; Mutation; Mutation Analysis; Nance-Horan syndrome; Partner in relationship; Patients; Phenotype; Purpose; Structure; Testing; Transgenes; Transgenic Animals; Transgenic Organisms; X Chromosome; Yeasts; antibiotic G 418; base; blastocyst; congenital cataract; design; disease-causing mutation; embryonic stem cell; genetic pedigree; human DNA sequencing; lens; mutant; prenatal; prevent; research study; vif Genes

Congenital cataracts, clinically defined as the presence of cataracts at birth, are the result of mutations in genes that are required for,proper lens development. The primary objective of this proposal is to identify the gene defective in the human X-linked cataract dental (XLCD) syndrome, a type of congenital cataract associated with microcornea and dental anomalies. Based on phenotype and location on the X chromosome, the Xcat mouse is the best animal model for human XLCD. We have positionally mapped Xcat through an interspecific backcross and identified two markers DxWas31 and DxPas18 that show no recombination with Xcat. Yeast artificial chromosome (YAC) and bacterial artificial chromosome (BAG) libraries were screened with these markers to develop a 900kb contig map of the Xcat critical region. The Xcat critical region will be refined through BAG transgenic complementation experiments designed to identify a single BAG that contains the Xcat gene. We will obtain the sequence of this BAG and analyze it for potential transcription units and ex Candidate Xcat genes will be screened for expression in the lens and by Southern zoo blots and database searches for conservation across species. Candidate genes that are conserved and expressed in prenatal lens will be evaluated for expression in Xcat mice. They will also be evaluated for mutations in the Xcat cDNA. The correlation between the mutant Xcat gene and the cataract phenotype will be confirmed by targeted disruption of Xcat in transgenic animals. Finally, the normal mouse Xcat sequence will be used to clone the corresponding normal human gene. After determining the structure of the normal XLCD gene, XLCD patients will be examined to determine if mutations in the Xcat human homolog are present. Identifying the XLCD gene would contribute to the our understanding of the molecular events involved in lens development.

先天性白内障，在临床上定义为出生时白内障的存在，是导致突变的结果 适当的晶状体开发所需的基因。该提案的主要目的是确定 基因在人X连锁白内障牙齿（XLCD）综合征中有缺陷，一种先天性白内障 与微孔和牙齿异常相关。基于X染色体上的表型和位置， XCAT小鼠是人XLCD的最佳动物模型。我们已经将XCAT映射到 种间反向交叉，并鉴定了两个标记DXWAS31和DXPAS18，这些标记均未显示与 XCAT。筛选酵母人工染色体（YAC）和细菌人造染色体（袋）库 使用这些标记来开发XCAT关键区域的900KB重叠图。 XCAT关键区域将是 通过袋子转基因补充实验精制，旨在识别一个包含的单袋 XCAT基因。我们将获得此袋的顺序，并分析潜在的转录单元和EX 候选XCAT基因将在镜头和南部动物园印迹和数据库中进行筛选 寻找跨物种的保护。在产前保守和表达的候选基因 镜头将在XCAT小鼠中评估。它们还将评估XCAT cDNA中的突变。 突变XCAT基因与白内障表型之间的相关性将由靶向 转基因动物中XCAT的破坏。最后，正常的鼠标XCAT序列将用于克隆 相应的正常人基因。确定正常XLCD基因的结构后， 将检查XLCD患者，以确定是否存在XCAT人类同源物中的突变。识别 XLCD基因将有助于我们对镜头中涉及的分子事件的理解 发展。