Identifying Cardiomyopathy Genes in Mice and Drosophila

鉴定小鼠和果蝇的心肌病基因

基本信息

批准号：
7141888
负责人：
Howard A Rockman
金额：
$ 38.88万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-09-29 至 2010-08-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Genetic approaches, preferentially in model systems that both allow accurate measurement of heart function as well as efficient genetic screening, are necessary for substantial progress in identifying the genetic basis of heart failure. In proposal, we will test the hypothesis that the powerful mutagen, N-ethyl-N- nitrosourea (ENU), mutagenesis in mice, and gene-deletion screens in Drosophila, will lead to the discovery of novel disease-causing and disease-modifying genes for human heart failure. In order to test these hypotheses, we have performed a recessive mutagenesis screen in adult mice at 8 and 16 weeks of age using non-invasive echocardiography to screen for abnormalities in cardiac function and have already identified a heritable region on chromosome 1 that maps to a cardiomyopathic phenotype. To complement the mouse studies we propose to use the fly to identify novel cardiomyopathic genes. Drosophila genetics provides more than 19,000 molecularly-defined P-elements inserted throughout the Drosophila genome that facilitate the generation of high-density genomic coverage. We have developed an innovative approach to phenotype cardiac function in adult awake Drosophila and have identified a P-element mutation in the short gastrulation (sog) gene that results in dilated cardiomyopathy. Based on our preliminary findings, we propose that mouse and Drosophila genetics can identify novel genes and mechanisms that are responsible for human dilated cardiomyopathies. Accordingly, we propose the following specific aims: Aim 1: To identify novel genes causing cardiomyopathy using an ENU phenotype-driven recessive screen in adult mice. We propose to map the disease causing gene located on chromosome 1 in the ENU family with abnormal cardiac function. Aim 2: To investigate the biochemical and genetic mechanisms through which mutations in the dpp/BMP signaling pathway lead to dilated cardiomyopathy in adult Drosophila. Genetic complementation experiments will be performed in Drosophila to prove that sog deficiency causes cardiomyopathy. Aim 3: To test whether decreased antagonism of the BMP pathway in mice, will result in a cardiomyopathic phenotype under conditions of pressure overload. TAG experiments will be performed in knock out mice deficient in the endogenous mammalian BMP antagonists chordin and noggin. Aim 4: To identify novel genes causing cardiomyopathy by performing a genome-wide screen of deletion mutants in Drosophila. Flies heterozygous for PiggyBac derived deletion mutants from the Exelixis collection will be screened for cardiomyopathy using optical coherence tomography followed by fine mapping of the disease-causing gene(s). Thus, these four integrated aims will harness the power of mouse and Drosophila genetics to identify and evaluate novel candidate genes for their role in cardiomyopathy.

描述（由申请人提供）：遗传方法，特别是在模型系统中，既可以精确测量心脏功能，又可以进行有效的遗传筛查，对于在确定心力衰竭的遗传基础方面取得实质性进展是必要的。在提案中，我们将测试以下假设：强大的诱变剂 N-乙基-N-亚硝基脲 (ENU)、小鼠诱变和果蝇基因删除筛选将导致新的致病和缓解疾病的发现人类心力衰竭的基因。为了检验这些假设，我们使用非侵入性超声心动图对 8 周和 16 周龄的成年小鼠进行了隐性诱变筛查，以筛查心脏功能异常，并且已经确定了 1 号染色体上的一个可遗传区域，该区域映射到心肌病表型。为了补充小鼠研究，我们建议使用果蝇来识别新的心肌病基因。果蝇遗传学提供了插入整个果蝇基因组的超过 19,000 个分子定义的 P 元件，有助于生成高密度基因组覆盖。我们开发了一种创新方法来检测成年清醒果蝇的心脏功能表型，并发现了短原肠胚形成 (sog) 基因中的 P 元件突变，该突变会导致扩张型心肌病。根据我们的初步发现，我们提出小鼠和果蝇遗传学可以识别导致人类扩张型心肌病的新基因和机制。因此，我们提出以下具体目标：目标 1：使用 ENU 表型驱动的隐性筛选成年小鼠来鉴定引起心肌病的新基因。我们建议对心脏功能异常的 ENU 家族中位于 1 号染色体上的致病基因进行定位。目标 2：研究 dpp/BMP 信号通路突变导致成年果蝇扩张型心肌病的生化和遗传机制。将在果蝇中进行基因互补实验，以证明 sog 缺乏会导致心肌病。目标 3：测试小鼠 BMP 通路拮抗作用的降低是否会导致压力超负荷条件下的心肌病表型。 TAG实验将在缺乏内源性哺乳动物BMP拮抗剂chordin和noggin的基因敲除小鼠中进行。目标 4：通过对果蝇中的缺失突变体进行全基因组筛选，鉴定引起心肌病的新基因。 Exelixis 收集的 PiggyBac 衍生缺失突变体杂合果蝇将使用光学相干断层扫描筛选心肌病，然后对致病基因进行精细定位。因此，这四个综合目标将利用小鼠和果蝇遗传学的力量来识别和评估新的候选基因在心肌病中的作用。