Analysis of the Exon Junction Complex in Neural Development and Microcephaly

这个职业发展建议的目标首先是扩大Pi在神经系统方面的培训， 第二，了解为什么RNA结合复合物成分的突变会导致 大脑体积缩小。为了实现第一个目标，我们制定了职业发展计划， 必要的科学和职业培训，使PI成为一名独立的顾问。为 在K99阶段的建议，这种培训将发生在NHGRI在NIH校园。本培训不可或缺的部分 是一个顾问小组，汇集了小鼠胚胎学，神经发育，小头畸形， 和有丝分裂为了实现第二个目标，我们将探索一种新的小头畸形小鼠模型， 被称为Mos 2。小头症是一种遗传性疾病，大脑体积显着减少 导致智力迟钝。有人提出小头畸形是由神经干缺陷引起的 发育中的新皮层细胞分裂。需要更多的模型来进一步验证这一点 概念.我们对Mos 2突变体的初步表征表明，神经干细胞功能受到损害， 在这些小鼠中，由于外显子连接复合物的一个组分发生突变，RNA结合复合物不 与神经发育有关在这个提议中，我们将测试这个复合体是 通过调节不对称细胞分裂来维持神经干细胞。首先，我们将描述 Mos 2突变体中的神经干细胞和分化的神经元群体，以评估神经干细胞 细胞功能被破坏。第二，我们将使用细胞生物学和遗传学方法来询问是否有其他 外显子连接复合物的组成部分调节大脑的大小。第三，我们将使用RNAi来测试 假设这种复合物是细胞分裂所必需的。该提案将为监管提供深入了解， 神经发育，小头畸形和其他神经发育疾病的机制，以及 具体解决RNA结合蛋白在这些过程中的作用。追求这些目标-将提供 作为一个独立的神经发育研究者的职业生涯的必要基础。

The objectives of this career development proposal are first to expand the Pi's training in neural development and second, to understand why mutation of an RNA-binding complex component causes reduced brain size. Towards the first objective we have formulated a career development plan to provide necessary scientific and career training for the PI to achieve success as an independent.investigator. For the K99 phase of the proposal, this training will occur at NHGRI on the NIH campus. Integral to this training is a panel of advisors that bring together expertise in mouse embryology, neural development, microcephaly, and mitosis. Towards the second objective we will explore a new mouse model of microcephaly we have identified called Mos2. Microcephaly is a genetic disorder in which brain size is significantly reduced resulting in mental retardation. It has been proposed that microcephaly is caused by defects in neural stem cell division in the developing neocortex. There is a need for additional models to further validate this concept. Our initial characterization of Mos2 mutants indicates that neural stem cell function is compromised in these mice due to mutation in a component of the exon junction complex, an RNA-binding complex not previously implicated in neural development. In this proposal we will test the hypothesis that this complex is required for neural stem cell maintenance by regulating asymmetric cell division. First we will characterize the neural stem cell and differentiated neuronal populations in Mos2 mutants to evaluate how neural stem cell function is disrupted. Second we will use cell biological and genetic approaches to ask if other components of the exon exon junction complex regulate brain size. Third, we will use RNAi to test the hypothesis that this complex is required for cell division. This proposal will provide insight into regulation of neural development, the mechanism of microcephaly and other neurodevelopmental diseases, and specifically address the role of RNA binding proteins in these processes. Pursuing these aims-will provide the necessary foundation for a career as an independent investigator in neural development.