A LINE-1 Retrotransposition-Deficient Mouse Genome

项目摘要 转座元件(TES)是一种离散的可移动DNA序列，其完整和突变的拷贝构成了 寄主基因组的很大一部分。在过去的十年里，大量的研究表明TES与进化有关 基因组和基因表达网络。然而，无论TES对发展还是对疾病有贡献都是一个 开放的关键问题回答，这可能会扩大甚至从根本上改变我们对基因 人类健康和病理学的基础。对人类健康特别感兴趣的是一种长时间穿插的 元素1(Line-1或L1)。例如，超过100种单基因人类疾病是由L1插入引起的。 有趣的是，最近的研究表明L1逆转座与正常发育有关(胚胎发生，卵子发生， 神经发生)、衰老和疾病(自身免疫性疾病、癌症)。然而，尽管有许多相关的 到目前为止，还没有研究确定L1逆转位在这些过程中的致病作用。初级阶段 研究内源性L1s的挑战在于哺乳动物基因组中存在大量全长完整的L1s。 转录或转录后水平的TE活性的实验性降低不能提供 在复杂组织中特异、稳定和长期的L1抑制。这份R21提案旨在迈出第一步 在我们对L1对发育和疾病的贡献的理解上，缩小这一差距。我们建议 一种逐步系统地灭活小鼠基因组中全长L1元件的实验策略 使用胚胎干细胞(ESC)模型。我们将监测和量化L1突变的程度和 最终确定候选的胚胎干细胞克隆，我们随后将在体内测试其发展潜力。这个 拟议的研究将为未来严格测试L1在开发和开发中的作用提供基础 疾病。 相关性 过去十年的研究表明，移动元件反转录转座子L1与健康发育和疾病有关。 如果是真的，这一论点将从根本上扩大我们对人类健康的基因基础的理解，并 病理学。我们建议通过系统地灭活猪的基因组中的L1元件来检验这一假说 小鼠胚胎干细胞及其活性L1缺失基因组的发育潜能 元素。

Project Summary Transposable elements (TEs) are discrete mobile DNA sequences whose intact and mutated copies constitute a substantial fraction of host genomes. Over the past decade, numerous studies implicated TEs in the evolution of genomes and gene expression networks. However, whether TEs contribute to development or disease is an open crucial question answering which might expand and even radically change our views on the genetic foundations of human health and pathology. Of particular interest to human health is a Long Interspersed Element 1 (LINE-1 or L1). For example, over a hundred single-gene human diseases arose from L1 insertions. Intriguingly, recent studies implicated L1 retrotransposition in normal development (embryogenesis, oogenesis, neurogenesis), aging and disease (autoimmune disorders, cancers). However, despite a multitude of correlative studies, none have established a causative role of L1 retrotransposition in these processes to date. The primary challenge of studying endogenous L1s lies in the large numbers of full-length intact L1s in mammalian genomes. Experimental reduction of TE activity at the transcriptional or post-transcriptional levels does not provide specific, stable and long-term L1 repression in complex tissues. This R21 proposal aims to make the first step toward closing this gap in our understanding of the contribution of L1 to development and disease. We propose an experimental strategy to gradually and systematically inactivate full-length L1 elements in the mouse genome using the embryonic stem cell (ESC) model. We will monitor and quantify the extent of L1 mutagenesis and ultimately identify candidate ESC clones whose developmental potential we will subsequently test in vivo. The proposed research will provide the foundation for future rigorous tests for the role of L1s in development and disease. Relevance Studies over the past decade implicated mobile element retrotransposon L1 in healthy development and disease. If true, this contention will radically expand our understanding of the genetic foundations of human health and pathology. We propose to test this hypothesis by systematically inactivating L1 elements in the genome of mouse embryonic stem cells and characterizing the developmental potential of genomes lacking active L1 elements.