Cloning and characterization of the Van Der Woude gene

描述(申请人提供)：唇腭裂是一种常见的先天性畸形，具有显著的终生发病率。广泛的心理、外科、言语和牙科介入强调了了解潜在原因的重要性。我们的长期目标是发现导致这种疾病的基因和环境因素。然而，唇腭裂的病因很复杂，鉴于大量基因被预测与孤立的唇腭裂有关，基因发现带来了巨大的挑战。这里使用的方法是研究一种遗传上简单的口裂模型--范德伍德综合征。范德伍德综合征是治疗孤立性唇腭裂的杰出临床模型，因为它唯一的特征是下唇凹陷。干扰素调节因子6(IRF6)突变导致范德伍德综合征。此外，IRF6的遗传变异增加了孤立性唇腭裂的风险，表明Van der Woude综合征也是一种杰出的遗传模式。因此，IRF6对于腭部发育的一个关键途径是必不可少的，它的发现代表了这一途径的一个立足点。这项建议的主要目的是通过首先确定IRF6在体内的功能，然后确定调节IRF6表达的因素来描述IRF6的途径。目的有3个：1)通过突变Irf6建立Van der Woude综合征小鼠模型，并对这些小鼠的腭部发育的致病过程进行全面的分析。由于IRF6是干扰素调节转录因子家族的成员，因此研究I型干扰素在小鼠味觉发育中的作用。2)探讨转化生长因子β3(Tgfbeta3)与Irf6基因突变之间潜在的遗传交互作用，因为Tgfa3对腭部发育和Irf6在腭部的表达是必需的。将对irf6和Tgfbeta3双重杂合子的小鼠进行味觉发育分析。同时，研究Irf6在腭部发育过程中转导Tgfbeta3信号的潜在作用。3)利用转基因小鼠鉴定调节腭部IRF6表达的增强子。Tgfbeta3是通过Smads还是通过其他转录因子调控IRF6，还是两者兼而有之？这些目标的完成将促进我们对IRF6在腭部发育中作用的理解，并识别可能导致孤立性唇腭裂的新的基因相互作用和基因，这是一种常见的人类疾病。这些知识将为加强诊断测试和未来的预防干预提供基础。

DESCRIPTION (provided by applicant): Cleft lip and palate is a common congenital anomaly with significant lifelong morbidity. The extensive psychological, surgical, speech and dental involvement emphasize the importance of understanding the underlying causes. Our long-term objective is to discover the genes and environmental factors that contribute to this disorder. However, the etiology of cleft lip and palate is complex, and given the large number of genes predicted to be involved in isolated cleft lip and palate, gene discovery poses a significant challenge. The approach used here will be to study a genetically simple model of orofacial clefting, Van der Woude syndrome. Van der Woude syndrome is an outstanding clinical model for isolated cleft lip and palate, as its only distinguishing features are pits in the lower lip. Mutations in Interferon Regulatory Factor 6 (IRF6) cause Van der Woude syndrome. Moreover, genetic variation in IRF6 confers risk for isolated cleft lip and palate, demonstrating that Van der Woude syndrome is also an outstanding genetic model. Thus, IRF6 is essential for a critical pathway in palate development, and its discovery represents a foothold in this pathway. The main goal of this proposal is to delineate the IRF6 pathway by first determining the in vivo function of IRF6 and then identifying factors that regulate the expression of IRF6. There are 3 Aims: 1) To generate a mouse model for Van der Woude syndrome by mutating Irf6, and to perform a comprehensive analysis of the pathogenic processes in palate development in these mice. To investigate a role for Type I interferons in palate development in mice, as IRF6 is a member of the Interferon Regulatory family of transcription factors. 2) To evaluate a potential genetic interaction between mutations in Irf6 and Transformation growth factor beta3 (Tgfbeta3), since Tgfa3 is necessary for palate development and for Irf6 expression in the palate. Mice that are double heterozygotes for Irf6 and Tgfbeta3 will be analyzed for palate development. Also, to examine the potential role for Irf6 in transducing the Tgfbeta3 signal during palate development. 3) To identify the enhancer that regulates Irf6 expression in the palate using transgenic mice. Does Tgfbeta3 regulate Irf6 through the SMADs or by other transcription factors or both? Completion of these aims will advance our understanding for the role of IRF6 in palate development, and identify novel gene interactions and genes that may contribute to isolated cleft lip and palate, a common human disorder. This knowledge will provide the basis for enhanced diagnostic tests and future preventive interventions.