Ocular Dysgenesis in Agrin Transgenic Mice

Agrin 转基因小鼠的眼部发育不全

• 批准号: 6851256
• 负责人: Robert W Burgess
• 金额: $ 16.9万
• 依托单位: JACKSON LABORATORY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6851256
• 关键词: agrin; biological models; congenital eye disorder; developmental genetics; developmental neurobiology; disease /disorder etiology; extracellular matrix; eye; gene mutation; genetic mapping; genetic models; genetic strain; genetic susceptibility; genetic techniques; genetically modified animals; genotype; histogenesis; laboratory mouse; molecular pathology; neurogenesis; phenotype; protein localization; protein quantitation /detection; protein structure function

DESCRIPTION (provided by applicant): Transgenic mice that over express the proteoglycan agrin have severe defects in ocular development. It is our hypothesis that this gain-of-function agrin mutation is perturbing eye development by disrupting the normal functions of the extracellular matrix (ECM) in the developing eye. The phenotype is also strain dependent, occurring only in a C57BL/6 genetic background, but with complete penetrance in that strain. Therefore, we also hypothesize that C57BL/6 mice provide a sensitized background for this phenotype, and that identifying the genes underlying this sensitivity will be relevant to related human conditions. The phenotype of the agrin-transgenic mice ranges from complete anophthalmia to corneal opacities caused by a failure of the lens to separate from the cornea. Frequently observed phenotypes include severe colobomas, a failure of lens to form, and an infiltration of pigmented fibrovascular tissue into the eye. The transgenic protein localizes to same structures that are affected. Based upon the localization of the transgenic protein and an increase in eye defects in a second, independent transgenic founder (though only at thirty percent initial penetrance) we conclude that the phenotype is a direct result of the presence of the transgenic protein in the eye. However, the possibilities that the phenotype is caused by a non-specific fetal stress response or by a mutation created by the transgene insertion have not been formally ruled out. The first specific aim of this proposal is to make this determination using a combination of genetic and molecular approaches. The phenotype is strain dependent and C57BL/6 mice are prone to spontaneous ocular defects at a rate of approximately five percent. The agrin-transgenic phenotypes resemble the severe extremes of the spontaneous defects. C57BL/6 provides a sensitized background for studying eye development, and the agrin-transgenic construct exacerbates this sensitivity. The second specific aim of this proposal is to use the agrin-transgenic mice in a classic genetic mapping experiment to identify the loci in the C57BL/6 background that predispose this strain to ocular dysgenesis. The haracterization of agrin overexpression as a tool for exploring the role of the ECM will open many new avenues of research. In addition, the identification of genes predisposing these transgenic mice to eye defects will be of great benefit to studies linking signaling molecules, environmental factors and protein effectors in both mice and humans.

描述（由申请人提供）：过度表达蛋白聚糖agrin的转基因小鼠在眼部发育中有严重的缺陷。我们的假设是，这种功能获得的Agrin突变正在通过破坏发育中的细胞外基质（ECM）的正常功能来扰动眼睛发育。表型也取决于应变，仅发生在C57BL/6遗传背景中，但在该菌株中完全渗透。 因此，我们还假设C57BL/6小鼠为这种表型提供了灵敏的背景，并且识别这种敏感性的基因将与相关的人类条件有关。 农业蛋白 - 转基因小鼠的表型范围从完全性质的性质因素到角膜泥泞，原因是镜头与角膜分离的失败引起的。经常观察到的表型包括严重的糖瘤，晶状体未能形成以及将色素的纤维血管组织浸润到眼睛中。转基因蛋白定位于受影响的相同结构。 基于转基因蛋白的定位以及在第二个独立的转基因创始人中的眼睛缺陷（尽管仅在30％的初始渗透率下），我们得出结论，表型是眼睛中转基因蛋白存在的直接结果。但是，表型是由非特异性胎儿应激反应或由转基因插入产生的突变引起的可能性，尚未正式排除。该提案的第一个具体目的是使用遗传和分子方法的组合来确定这一确定。表型与应变相关，C57BL/6小鼠容易以大约5％的速度自发眼缺损。 Agrin-转基因表型类似于自发缺陷的严重极端。 C57BL/6为研究眼睛发育提供了灵敏的背景，而Agrin-Transgenic构建体会加剧这种敏感性。该提案的第二个具体目的是在经典的遗传映射实验中使用Agrin-转基因小鼠，以识别C57BL/6背景中的基因座，使这种菌株易于眼发性障碍。 Agrin过表达作为探索ECM作用的工具的恶劣化将开放许多新的研究途径。此外，鉴于诱发这些转基因小鼠眼缺陷的基因将对研究小鼠和人类的信号分子，环境因素和蛋白质效应子的研究具有很大的好处。