Neuronal CpG Methylation During Development in Normal and Adverse Environment

描述(申请人提供)：DNA甲基化与神经元功能和精神障碍有关，但这些研究仅限于少数候选基因。要了解DNA甲基化在神经元发育和疾病中的作用，需要了解甲基化胞嘧啶在整个基因组和特定神经元原型中的分布，这些原型的功能可以直接与正常和病理行为联系起来。在这里，我们建议i)使用具有代表性的全基因组DNA甲基化分析来表征mCpGs在海马区和纹状体的谷氨酸能和GABA能投射神经元中的分布，以及在发育过程中跟随甲基化的神经元前体和小鼠胚胎干细胞。本研究选择的神经元参与重要的功能，包括空间学习/记忆(背侧海马体)、情绪行为(腹侧海马体)、运动活动(背侧纹状体)以及药物滥用和社会行为(腹侧纹状体/伏隔核)。由于所有这些行为都受到母体环境的影响，我们还建议II)确定出生前/早期不利的母体环境对对这些影响敏感和有弹性的动物神经元DNA甲基化的影响。我们之前已经建立了两个动物模型，这两个模型基于母体突变导致遗传正常的后代出现永久性行为异常，包括异常恐惧、应激反应、整体活动和社会互动。我们期望我们的研究将识别出a)神经元原型，b)它们的发育阶段(神经元前体，年轻和成熟的神经元)，c)它们的背腹位置和d)不利的母体影响的DNA甲基化特征。这项建议中使用的高分辨率甲基化分析不仅有助于确定甲基化的总体模式，而且还有助于产生以甲基化为标志的基因组合。这些基因组形成了功能网络和途径，这对于理解DNA甲基化在神经元发育和精神疾病中的作用至关重要。

DESCRIPTION (provided by applicant): DNA methylation has been implicated in neuronal functions and mental disorders but these studies were limited to a few candidate genes. Understanding the role of DNA methylation in neuronal development and disease requires knowledge of the distribution of methylated cytosines in the entire genome and in specific neuronal prototypes whose function can be directly linked to normal and pathological behavior. Here we propose i) to employ genome-wide representational DNA methylation analyses to characterize the distribution of mCpGs in glutamatergic and GABAergic projection neurons in the hippocampus and striatum, respectively, as well as in neuronal precursors and mouse embryonic stem (ES) cells to follow methylation during development. The neurons selected for this study are involved in important functions including spatial learning/memory (dorsal hippocampus), emotional behavior (ventral hippocampus), locomotor activity (dorsal striatum) and drug abuse and social behavior (ventral striatum/nucleus accumbens). Since all of these behaviors are influenced by the maternal environment, we also propose ii) to determine the effect of adverse pre/early postnatal maternal environment on neuronal DNA methylation in animals sensitive and resilient to these effects. We have previously established two animal models which are based on maternal mutations leading to permanent behavioral abnormalities in genetically normal offspring, including abnormal fear, stress responsiveness, overall activity and social interaction. We expect that our studies will identify DNA methylation signatures specific a) for neuronal prototypes, b) for their developmental stages (neuronal precursor, young and mature neurons), c) for their dorso-ventral position and d) for adverse maternal effects. The high resolution methylation assay used in this proposal will help to determine not only the overall pattern of methylation but also to generate assemblies of genes marked by methylation. These groups of genes form functional networks and pathways that are essential to understand the role of DNA methylation in neuronal development and psychiatric disease.