Finding the Mouse Disorganization Gene

描述（由申请人提供）：出生缺陷在人类中经常发生，但大多数情况下是散发的，没有明显的遗传或环境病因。小鼠突变失组织（Ds）是单基因孟德尔特征的一个非凡例子，由于其特殊的遗传和发育特征，它具有零星的发生模式。d是一个罕见的以真正的显性和功能获得方式遗传的特征的例子。它的发展属性更引人注目。d会导致各种各样的出生缺陷，涉及到身体的大部分部位，但值得注意的是，没有两只老鼠受到同样的影响。缺陷通常是不对称的，但在受影响的结构中往往表现为镜像对称。各种出生缺陷的性质表明，在胚胎发育过程中，紊乱基因在模式形成和谱系确定中起着基本作用，而突变的性质导致正常发育模式中不可预测的异常。在之前的资助期间，我们在Ds位点发现了一个新的ETnII转座元件插入，以及一个带有该元件和三个侧翼基因的BAC，这些基因可以在转基因小鼠中引起类似紊乱的出生缺陷。然而，这个ETnll插入在基因之间的位置表明，它没有破坏编码序列，而是可能导致嵌合转录物，它可能对侧翼基因的表达产生不利影响，或者插入可能破坏了非编码功能元件。为了鉴定Ds基因，我们提出了特异性目标1：完成Ds小鼠中完成的序列与产生Ds突变的DA/Hu菌株中相应序列的比较；特异性目的2：检测3个候选基因在DS/Ei和DA/Hu胚胎发育过程中的表达模式（嵌合转录物和mRNA水平）；特异性目的3：检测BAC转基因的受影响小鼠，野生型小鼠中Ds位点的ETnll敲入突变体，以及野生型小鼠中三种侧翼基因普遍过表达的功能后果。这些系统的研究将导致鉴定紊乱基因，并深入了解基本发育过程的控制和零星出生缺陷产生的方式。

DESCRIPTION (provided by applicant): Birth defects occur frequently in humans but occurrence in most cases is sporadic without obvious genetic or environmental etiology. The mouse mutation Disorganization (Ds) is an extraordinary example of a single gene Mendelian trait that has sporadic patterns of occurrence because of its exceptional genetic and developmental features. Ds is one of the rare examples of a trait that is inherited in a true-dominant and gain-of-function manner. Its developmental attributes are even more striking. Ds causes an extraordinary variety of birth defects involving most body parts, but remarkably no two mice are affected in the same way. The defects are always asymmetrical but often show mirror-image symmetry in the affected structure. The nature of the various birth defects suggests both that the Disorganization gene plays a fundamental role in pattern formation and lineage determination during embryonic development, and the nature of the mutation leads to unpredictable anomalies in the normal patterns of development. During the previous funding period, we discovered a new insertion of an ETnII transposable element at the Ds locus, and a BAC with this element and three flanking genes that can cause Disorganization-like birth defects in transgenic mice. However, the location of this ETnll insertion between genes suggests that it did not disrupt coding sequences, but instead may cause chimeric transcripts, it may adversely affect the expression of flanking genes, or the insertion may have disrupted a non-coding functional element. To identify the Ds gene, we propose Specific Aim 1: to complete the comparison between the finished sequence in Ds mice with the corresponding sequence in the DA/Hu strain on which the Ds mutation arose; Specific Aim 2: to test expression patterns (chimeric transcripts and mRNA levels) of the three candidate genes during embryonic development in DS/Ei and DA/Hu embryos; and Specific Aim 3: to test for affected mice in BAC transgenics, ETnll knock-in mutants at the Ds locus in wild-type mice, and the functional consequences of ubiquitous over-expression of each of the three flanking genes in wild-type mice. These systematic studies should lead to identification of the Disorganization gene and to insights into the control of fundamental developmental processes and the ways in which sporadic birth defects arise.