Molecular control of brain size

大脑大小的分子控制

基本信息

批准号：
9002106
负责人：
BYOUNG-IL BAE
金额：
$ 20.9万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-10-22 至 2018-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9002106
关键词：
Address Alleles Animal Model Behavior Brain Centrioles Centrosome Cerebral Palsy Cerebral cortex Cerebrum Cognitive Cortical Malformation DNA Sequence Alteration Data Daughter Defect Development Epilepsy Evolution Ferrets Genes Genetic Genetic Engineering Genetic study Green Fluorescent Proteins Health Human Human Genetics Image Immunoelectron Microscopy Immunohistochemistry Infection Intellectual functioning disability Investigation Knock-out Knockout Mice Knowledge Language Delays Location Maintenance Measures Mental Health Microcephaly Modeling Molecular Mothers Mus Mutate Mutation Neurodevelopmental Disorder Neuroglia Neurologic Neurons Patients Phenotype Population Primates Proteins Radial Reporting Resolution Role Slice Symptoms System Thick Time Variant WD Repeat Work autism spectrum disorder brain size brain volume fly gene product genome editing in vivo innovation insight mouse model nerve stem cell novel premature progenitor tool transcription activator-like effector nucleases transmission process

项目摘要

DESCRIPTION (provided by applicant): Microcephaly ("abnormally small brain") is a neurodevelopmental disorder that causes neurological symptoms, such as intellectual disability, language delay, and epilepsy. A number of causative genes have been reported, the majority of which encode centrosomal proteins. Exactly how mutations in centrosomal proteins cause microcephaly is not well understood. Previous studies using fly and mouse models suggest that mutations in centrosomal proteins may disrupt proliferation of neural progenitor cells (NPCs) or induce premature differentiation into neurons at the expense of NPCs. However, currently available animal models of microcephaly have pretty mild phenotypes, making it hard to address which molecular and cellular mechanisms are critical to severe microcephaly in humans. This project seeks to develop and establish new animal models for microcephaly with robust phenotypes. We have two hypotheses: (1) because many microcephaly gene products colocalize in the centrosome, some of them may interact biochemically and genetically. For example, ASPM (abnormal spindle-like, microcephaly-associated) and WDR62 (WD repeat domain 62), the two most common causes for human microcephaly when mutated, interact with each other. Thus, heterozygous deletion of one microcephaly gene, which has no phenotype at all by itself, may enhance the mild phenotype in homozygous knockout mice of another microcephaly gene; (2) Unlike mice, ferrets have an enlarged brain, which contains outer radial glial cells, a type of NPCs that is highly abundant in the human cortex. Thus, knockout ferrets of a microcephaly gene may show robust phenotypes compared to knockout mice of the same gene. In Aim 1, we will examine Aspm-/-; Wdr62+/- mice that have a significantly smaller brain than any control mice (Aspm+/+; Wdr62+/- and Aspm-/-; Wdr62+/+ mice), which have negligible phenotypes. We will characterize interaction between the two proteins as well as asymmetric inheritance of mother versus daughter centrosomes in the developing cortex of Aspm-/-; Wdr62+/- mice. In Aim 2, we will establish and characterize Aspm-knockout ferrets that we have recently generated using TALEN, a new genome-editing tool. Preliminary data show that they have severe microcephaly. Using immunohistochemistry and adenoviral green fluorescent protein infection followed by time-lapse imaging, we will examine abundance and behaviors of diverse NPCs in Aspm-knockout and wile-type ferrets. The proposed work will provide exciting new animal models for microcephaly and cortical malformation in general, creating an innovative experimental system in the field of cerebral cortical development and evolution. With ever-increasing list of genes from human genetic studies, our approach will demonstrate how to study functional meanings of a gene when knockout mice of the gene do not show robust phenotypes. In addition, it should resolve the current debate over roles of outer radial glial cell during cerebral cortical development, and has the potential to identify novel mechanisms of normal cortical development.

描述（应用程序提供）：小头畸形（“异常小脑”）是一种神经发育障碍，会导致神经系统症状，例如智力障碍，语言延迟和癫痫病。已经报道了许多属，其中大多数编码了中心体蛋白。确切的中心蛋白突变如何引起小头畸形。先前使用Fly和小鼠模型的研究表明，中心蛋白中的突变可能破坏神经元祖细胞（NPC）的增殖或以NPC为代价诱导神经元的过早分化。但是，当前可用的小头畸形动物模型具有相当温和的表型，因此很难解决哪些分子和细胞机制对于人类的严重小头畸形至关重要。该项目旨在通过健壮的表型开发和建立新的小头畸形动物模型。我们有两个假设：（1）因为许多小头畸形基因产物在中心体中共定位，因此其中一些可能在生化和遗传上相互作用。例如，ASPM（异常纺锤体样，小头畸形相关）和WDR62（WD重复结构域62），这是人类小头畸形时最常见的两个原因，当突变时，相互相互作用。这是一个单独没有表型的一个微畸形基因的杂合缺失，可能会增强另一个小头畸形基因的纯合敲除小鼠中的中表型。（2）与小鼠不同，雪貂具有肿大的大脑，其中包含径向神经胶质细胞，这是一种在人皮质中高度丰富的NPC。与同一基因的基因敲除小鼠相比，小头畸形基因的基因敲除雪霉可能表现出强大的表型。在AIM 1中，我们将检查ASPM - / - ; WDR62 +/-小鼠的大脑明显小于任何对照小鼠（ASPM+/+; WDR62 +/-和ASPM - / - ; WDR62 +/-小鼠），它们具有可忽略的表型。我们将表征两种蛋白质之间的相互作用，以及在ASPM的发展皮层中，母亲与子中心体的不对称遗传 - / - ; WDR62 +/-小鼠。在AIM 2中，我们将建立并表征我们最近使用一种新的基因组编辑工具Talen生成的ASPM-KNOCKOUT雪貂。初步数据表明它们具有严重的小头畸形。使用免疫组织化学和腺病毒绿色荧光蛋白感染，然后进行延时成像，我们将检查ASPM-KNOCKOUT和WILE型雪貂中潜水员NPC的丰度和行为。拟议的工作将为一般的小头畸形和皮质畸形提供令人兴奋的新动物模型，从而在脑皮质发育和进化领域创造了创新的实验系统。随着来自人类遗传研究的基因列表的不断增长，我们的方法将演示如何研究基因的基因敲除小鼠的功能含义。此外，它应该解决脑皮质发育过程中径向神经胶质细胞的作用的当前调试，并具有鉴定正常皮质发育的新机制的潜力。