Mammalian Heart and Lung microRNA Deletion and Distribution Resource

描述（由申请人提供）： 大多数对基因功能的生物学分析都集中在蛋白质编码基因上，这些基因仅占人类基因组的1.4%。基因组的其余部分基本上未被探索。最近发现的保守的非编码RNA片段，包括microRNA（miRNA），揭示了一个以前未被认识的基因组调控层。长度为20-22个核苷酸的miRNA在转录后起作用以滴定基因组中至少三分之一的蛋白质编码基因的活性。在某些情况下，miRNA作为关键通路的开关。在其他情况下，它们作为变阻器来滴定正常生物学中的通路活动以及对外部压力和刺激的反应。虽然已经鉴定了超过450种人类或小鼠的miRNAs，但这类新的RNA的大部分知识来自蠕虫和苍蝇。迄今为止，仅报道了三种miRNA在小鼠中的靶向缺失，其中两种在心脏生物学中具有关键功能。这些早期的功能丧失研究揭示了干预人类疾病的新靶点，并且很可能破坏其他miRNAs也同样具有启发性。 为了促进这一新兴和高度重要的生物学领域的发现，我们建议用一种先进的遗传修饰胚胎干细胞的策略来消除小鼠中进化上保守的心脏和肺富集的miRNA基因。这些小鼠将通过基于网络的机制提供给科学界，以加速心脏和肺研究几乎所有方面的进展。这是一项雄心勃勃的努力，但我们相信我们拥有独特的工具和专业知识来完成它。此外，回报可能很大。我们期待着对基因组中这一相对未被探索的部分的理解会有重大突破。新的人类疾病小鼠模型可以揭示人类疾病，其中潜在的蛋白质编码疾病基因很难在给定的遗传基因座内进行定位。这些疾病包括发育和产后维护和适应的一系列心脏和肺部疾病。为了完成这个项目，我们提出了三个具体目标。 具体目标1。产生胚胎干细胞和破坏约75个心脏和肺富集miRNAs的小鼠。 具体目标2。完成miRNA缺失系的初步表征，包括破坏验证和内源性miRNA表达分析。 具体目标3。向科学界传播有关miRNA-disrupted小鼠品系的信息并协调交付。 (End摘要）

DESCRIPTION (provided by applicant): Most biological analyses of gene function have focused on protein-encoding genes, which constitute a mere 1.4% of the human genome. The rest of the genome is largely unexplored. The recent discovery of conserved stretches of non-coding RNAs, including microRNAs (miRNAs), has revealed a previously unrecognized layer of genomic regulation. miRNAs 20-22 nucleotides in length, function post-transcriptionally to titrate the activity of at least one-third of the protein-coding genes in the genome. In some cases, miRNAs function as on-off switches for key pathways. In other situations, they function as a rheostat to titrate the activity of pathways in normal biology and in response to external stresses and stimuli. Although more than 450 human or mouse miRNAs have been identified, most of the knowledge of this novel class of RNAs has come from worms and flies. Targeted deletion in mice has been reported for only three miRNAs to date, with two of them having critical functions in cardiac biology. These early loss-of-function studies have revealed novel targets for intervention in human disease, and it is highly likely that disruption of additional miRNAs will be equally revealing. To catalyze discovery in this emerging and highly significant area of biology, we propose to ablate -75 evolutionarily conserved heart and lung-enriched miRNA genes in the mouse with an advanced strategy to genetically modify embryonic stem cells. These mice will be made available to the scientific community through a web-based mechanism to accelerate advances in virtually every aspect of heart and lung research. This is an ambitious effort, but we believe we have the unique tools and expertise to accomplish it. In addition, the payoff is potentially significant. We expect major breakthroughs in the understanding of this relatively unexplored portion of the genome. New mouse models of human disease could shed light on human diseases in which potential protein-encoding disease genes have been difficult to map within a given genetic locus. These include a host of cardiac and pulmonary diseases of development and post-natal maintenance and adaptation. To accomplish this project, we propose three specific aims. Specific Aim 1. To generate embryonic stem cells and mice with disruption of ~75 heart and lung-enriched miRNAs. Specific Aim 2. To complete an initial characterization of the miRNA deletion lines, including validation of disruption and analysis of endogenous miRNA expression. Specific Aim 3. To disseminate information on and coordinate delivery of miRNA-disrupted mouse lines to the scientific community. (End of Abstract)