GENETIC AND MOLECULAR ANALYSES OF MOUSE MUTATIONS

这项研究计划的长期目标是了解 粉眼小鼠复杂哺乳动物基因座的表型多样性 稀释轨迹。根据定义，该基因座的所有突变等位基因都会影响 色素沉着。然而，几个突变的等位基因表现出额外的 表型，包括不孕症、腭裂和两种截然不同的 神经功能障碍(剧烈运动和震颤)。所有的等位基因 有无色素沉着的表型是由辐射诱导的 突变；初步研究表明，这些突变是由 删除(或颠倒)。这些缺失的重叠模式， 结合突变等位基因的互补性分析，表明 几个(紧密相连的)基因导致了不同的表型。 粉色眼睛稀释型突变体。定义与之相关的基因的区域 不孕症、神经疾病和腭裂的表型有 已经本地化了。这项提案的三个具体目标是直接的 对这些基因的分离和鉴定。它们是：1) 为粉眼患者绘制一份全面的身体和基因图谱 分子生物学技术(包括脉冲场)稀释轨迹 凝胶电泳)和对复合突变体的分析。2)至 确定神经学和生育问题的分子基础 通过对~30kb区域的系统分析获得特定的突变等位基因 与这些表型相关。3)进行神经病理检查和 一种与震颤和腭裂相关的突变等位基因的组织病理学， 并鉴定和分离与这些基因相关的候选基因 表型。 这项研究对人类健康问题有三个主要影响：1)人类 粉眼稀释轨迹的共线区与两个 遗传性疾病、Prader-Willi综合征和Angelman综合征 它有一些相同的表型。2)编码受体的基因 在突变体中，GABA(一种抑制性神经递质)亚单位被删除 表现震颤的等位基因，为研究GABA提供了一个独特的模型 系统紊乱，如癫痫。3)与之相关的突变等位基因 腭裂为研究分子提供了一个无与伦比的模型系统 一种隐性的腭裂的基础。一个基因的鉴定 与腭裂(一种常见的人类出生缺陷)相关的将代表一种 在努力了解腭裂的病因方面迈出了重要的一步。

The long term objective of this research program is to understand the phenotypic diversity of a complex mammalian locus, the mouse pink-eyed dilution locus. By definition, all mutant alleles of this locus affect pigmentation. However, several mutant alleles exhibit additional phenotypes, including sterility, cleft palate, and two distinct neurological disorders (jerky movement and tremors). All of the alleles with non-pigmentation phenotypes were derived by radiation-induced mutagenesis; preliminary studies indicate that these mutations result from deletions (or inversions). The pattern of overlap of these deletions, combined with complementation analysis of mutant alleles, imply that several (closely linked) genes are responsible for the diverse phenotypes of pink-eyed dilution mutants. Regions defining the genes associated with the phenotypes of sterility, neurological disorders and cleft palate have been localized. The three specific aims of this proposal are directed towards the isolation and characterization of these genes. They are: 1) To develop a comprehensive physical and genetic map of the pink-eyed dilution locus by molecular biological techniques (including pulsed-field gel electrophoresis) and by the analysis of compound mutants. 2) To determine the molecular basis of the neurological and fertility problems of specific mutant alleles by the methodical analysis of a region of ~30 kb associated with these phenotypes. 3) To determine the neuropathology and histopathology of a mutant allele associated with tremors and cleft palate, and to identify and isolate candidate genes associated with these phenotypes. This research has three major impacts on human health issues: 1) The human syntenic region of the pink-eyed dilution locus is associated with two genetic diseases, Prader-Willi Syndrome and Angelman Syndrome, with which it shares some of the same phenotypes. 2) A gene encoding a receptor subunit for GABA (an inhibitory neurotransmitter) is deleted in the mutant allele exhibiting tremors, providing a unique model for studying GABA system disorders, such as epilepsy. 3) The mutant allele associated with cleft palate offers an unparalleled model system to study the molecular basis of a recessive form of cleft palate. The identification of a gene associated with cleft palate (a common human birth defect) will represent a significant step in the efforts to understand the etiology of cleft palate.