Temporal, cell type- and locus-specific epigenetic control in transgenic mice

描述（由申请人提供）：哺乳动物器官由多种混合的细胞类型组成，其完整程度和多样性尚不清楚。从单细胞胚胎到任何终末分化的细胞（如成年神经元），细胞身份的规范和维持在很大程度上依赖于表观遗传机制，这些机制作用于基因组，以实现或阻止特定基因组的表达。在这样做的过程中，基因表达的表观遗传调控使得单个基因组能够在多细胞生物体中编码多种细胞类型。表观遗传修饰确保细胞通过一组有限的基因表达可能性进行，并且一旦分化，细胞在其整个生命周期中保持其表型。因此，表观遗传修饰的破坏可能导致各种疾病，包括神经发育和精神疾病以及癌症。我们建议开发一套小鼠转基因工具，有可能改变表观遗传修饰的方式，可以在这个哺乳动物模型系统中进行研究和理解。这些新工具将在各种细胞类型及其祖细胞中提供表观遗传修饰剂的调节表达，同时永久标记这些细胞或其后代，以便在以后的任何时间点进行检查。此外，我们还将开发一种技术，使小鼠基因组中的一个位点在动物生命的特定时间和特定细胞中受到表观遗传干扰。我们将利用这些工具来了解皮质中的细胞类型身份以及负责产生和维持这种身份的机制。表观遗传调节因子与许多脑部疾病有关，我们正在开发的工具将有助于建模或测试与表观遗传现象扰动相关的特定假设。所获得的见解也可以为体外产生特定细胞类型提供指导，并为体内“重新利用”某些细胞类型提供指导。虽然我们的研究重点将放在小鼠大脑上，但我们工具的多功能和模块化设计将使他们能够进行研究。 用于研究任何其他组织或细胞类型的发育、功能或疾病。我们将确保容易获得我们生成的所有工具，以最大限度地发挥其对理解哺乳动物生物学各个方面的影响。

DESCRIPTION (provided by applicant): Mammalian organs are built of a variety of intermingled cell types, the full extent and diversity of which are unknown. Specification and maintenance of cell identity, from a single cell embryo to any terminally differentiated cell such as an adult neuron, rely heavily on epigenetic mechanisms that act upon the genome to enable or prevent expression of specific sets of genes. In doing so, epigenetic regulation of gene expression enables a single genome to encode a diverse array of cell types in a multicellular organism. Epigenetic modifications ensure that a cell proceeds through a limited set of gene expression possibilities, and once differentiated, that a cell maintains its phenotype throughout its lifetime. As a consequence, disruption of epigenetic modification can result in a variety of diseases, including neurodevelopmental and psychiatric diseases, and cancer. We propose to develop a set of mouse transgenic tools that have the potential to transform the way epigenetic modifications can be studied and understood in this mammalian model system. The new tools will provide regulated expression of epigenetic modifiers in a variety of cell types and their progenitors, while permanently marking these cells or their progeny for examination at any later time point. Moreover, we will develop technology, in which a single locus in the mouse genome can be subjected to epigenetic perturbations in specific cells and at specific times in the animal's life. We will employ these tools to gain understanding of cell-type identity in the cortex as well as the mechanisms responsible for generating and maintaining this identity. Epigenetic regulators have been implicated in a number of brain diseases, and the tools we are developing will facilitate modeling or testing specific hypotheses that relate to perturbations of epigenetic phenomena. The insights gained may also provide guidance for the generation of specific cell types in vitro, and directions for 'repurposing' certain cell types in vivo. Although the focus of ur studies will be on the mouse brain, the versatile and modular design of our tools will enable their use in studying development, function or disease in any other tissue or cell type. We will ensure easy access to all tools we generate to maximize their impact on understanding various aspects of mammalian biology.