Implication of the DotCom complex members AF9 and DOT1L in cerebral cortex development

DotCom 复合体成员 AF9 和 DOT1L 对大脑皮层发育的影响

• 批准号: 290647137
• 负责人: Professorin Dr. Tanja Vogel
• 金额: --
• 依托单位: Anatomie II: Abteilung für Molekulare Embryologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/290647137?language=en
• 关键词: Implication; DotCom; complex; members; AF9

Neuronal specification of neural stem cells predominates embryonic development of the stratified cerebral cortex. Neural stem cells reside in two cellular compartments and produce either lower or upper layer neurons. The latter are produced by stem cells from the subventricular zone, which are not well characterised on a molecular level. However, they play a pivotal role during evolution of higher cognitive tasks. In this project we aim to further characterise these determined stem cells.Our preliminary data identified AF9/MLLT3 (myeloid/lymphoid or mixed-lineage leukemia (trithorax homolog, Drosophila); translocated to, 3) as transcription factor that suppresses upper layer fate and influences subventricular progenitor proliferation. We are now addressing the question how AF9 controls progenitor proliferation and differentiation. AF9 acts in different protein complexes: on one hand in the DotCom that contains the histone methyltransferase DOT1L (DOT1-like, histone H3 methyltransferase), and on the other hand in the super elongation complex (SEC) that is implicated in transcriptional elongation. We will generate AF9- and DOT1L-deficient mice and characterise progenitor and neuronal specification in a context of a hierarchical developmental sequence involving a variety of transcription factors. We will further identify target genes for AF9 and DOT1L specifically in subventricular progenitors using high throughput sequencing of RNA. Targets will be classified according to DOT1L-dependent and -independent transcription. Using chromatin-immunoprecipitation we will elucidate genome-wide distribution of specific chromatin modifications, RNA polymerase II, AF9 and DOT1L to define presence of DotCom or SEC proteins at the respective AF9 target gene loci in the context of subventricular progenitor specification. We will thus provide data about transcriptional control through transcription factors that act via chromatin modifications during cortical development. Furthermore we will provide insights into the developmental capacities of a specific stem cell population that gives rise to neuronal networks implicated in higher cognitive tasks.

神经干细胞的神经元特化在复层大脑皮层的胚胎发育中占主导地位。神经干细胞存在于两个细胞区室中，并产生下层或上层神经元。后者是由室管膜下区的干细胞产生的，在分子水平上还没有很好的表征。然而，它们在高级认知任务的进化过程中起着关键作用。我们的初步数据确定AF 9/MLLT 3（髓样/淋巴样或混合系白血病（三胸同源物，果蝇）;易位到，3）作为抑制上层命运和影响室下祖细胞增殖的转录因子。我们现在解决的问题是AF 9如何控制祖细胞增殖和分化。AF 9在不同的蛋白质复合物中起作用：一方面在含有组蛋白甲基转移酶DOT 1 L（DOT 1样，组蛋白H3甲基转移酶）的DotCom中，另一方面在涉及转录延伸的超延伸复合物（SEC）中。我们将产生AF 9-和DOT 1 L-缺陷的小鼠，并在涉及多种转录因子的分层发育序列的背景下，对祖细胞和神经元进行规范。我们将使用高通量RNA测序进一步鉴定室下祖细胞中特异性AF 9和DOT 1 L的靶基因。将根据DOT 1 L依赖性和非依赖性转录对靶标进行分类。使用染色质免疫沉淀，我们将阐明特定的染色质修饰，RNA聚合酶II，AF 9和DOT 1 L的全基因组分布，以确定存在的DotCom或SEC蛋白在各自的AF 9靶基因位点的上下文中室下祖细胞规范。因此，我们将提供有关转录控制的数据，通过转录因子，通过染色质修饰在皮质发育过程中发挥作用。此外，我们将提供一个特定的干细胞群体的发展能力，引起涉及更高的认知任务的神经元网络的见解。