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，但在大多数情况下是散发性的，没有明显的遗传或环境病因。小鼠突变Disorganization（Ds）是单基因孟德尔性状的一个特殊例子，由于其特殊的遗传和发育特征，它具有零星的发生模式。DS是以真显性和功能获得方式遗传的性状的罕见例子之一。它的发展属性甚至更加引人注目。Ds导致了一系列涉及身体大部分部位的出生缺陷，但值得注意的是，没有两只老鼠受到同样的影响。这些缺陷总是不对称的，但在受影响的结构中常常表现出镜像对称。各种出生缺陷的性质表明，Disorganization基因在胚胎发育过程中的模式形成和谱系决定中起着重要作用，突变的性质导致正常发育模式中不可预测的异常。在上一个资助期间，我们发现了一个新的插入ETnII转座因子在Ds位点，和BAC与此元素和三个侧翼基因，可以导致混乱样出生缺陷的转基因小鼠。然而，该ETnII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，它可能不利地影响侧翼基因的表达，或者插入可能破坏了非编码功能元件。为了鉴定Ds基因，我们提出了具体目标1：完成Ds小鼠中完成的序列与发生Ds突变的DA/Hu品系中相应序列的比较;具体目标2：检测表达模式DS/Ei和DA/Hu胚胎中胚胎发育期间三种候选基因的表达水平（嵌合转录物和mRNA水平）;以及特异性目标3：以测试BAC转基因中受影响的小鼠、野生型小鼠中Ds基因座处的ETnII敲入突变体以及野生型小鼠中三个侧翼基因中的每一个的普遍过表达的功能后果。这些系统性的研究将有助于我们识别解体基因，并深入了解基本发育过程的控制以及偶发性出生缺陷的产生方式。

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.