Characterizing the functions of a microcephaly-related gene in a knock-out mouse model using in vivo MRI, histology and cellular/molecular biology app

人类“贩运蛋白颗粒复合物亚基9”（TRAPPC 9）基因的突变会导致小头畸形、智力残疾、语言障碍和发育迟缓。该蛋白质在调节细胞内运输和囊泡大小中起作用。在这个项目中，我们将使用一种新的Trappc9 KO系，因为我们的初步未发表数据通过高分辨率磁共振成像（显微镜MRI）测量脑重量和脑体积证实了年轻成年突变体中的小头畸形。我们的特点的Trappc9表达模式在一个子集的神经元和神经祖细胞（NPC）的大脑和神经球文化。我们发现海马齿状回Sox 2阳性NPC减少，但其他成人神经原性区域尚未研究。目标一：使用MRI和组织学评估Trappc9缺陷型脑的异常，并确定小头畸形的发育发作。由于发展发病的小头畸形是不清楚的，我们将进行纵向在体内的MRI研究，以检查总脑容量在不同的出生后和青少年stages.Objective 2：功能评估的神经祖细胞在体内和体外，并确定在囊泡运输和亚细胞区室在原代神经元培养的缺陷。离体，我们将评估NPC的增殖和分化使用神经球培养。

Mutations in the human 'Trafficking protein particle complex subunit 9' (TRAPPC9) gene cause microcephaly, intellectual disability, speech impairment and developmental delays. The protein functions in the regulation of intracellular transport and vesicle size. In this project we will use a novel Trappc9 KO line as our preliminary unpublished data confirms microcephaly in young adult mutants through measurements of brain weights as well as brain volumes via high-resolution magnetic resonance imaging (microscopic MRI). We characterised the Trappc9 expression pattern in a subset of neurons and neural progenitor cells (NPCs) of the brain and in neurosphere cultures. We found a reduction in Sox2-positive NPCs in the hippocampal dentate gyrus, but other adult neurogenic regions have not yet been investigated. Objective 1: Evaluation of abnormalities in Trappc9 deficient brains using MRI and histology, and determination of the developmental onset of microcephaly. Since the developmental onset of microcephaly is unclear, we will undertake a longitudinal in vivo MRI study to examine total brain volumes at various postnatal and juvenile stages.Objective 2: Functional assessment of neural progenitor cells in vivo and ex vivo, and determination of deficiencies in vesicle transport and sub-cellular compartments in primary neuronal cultures. Ex vivo, we will assess NPC proliferation and differentiation using neurosphere cultures.