Epigenetic regulatory mechanisms during neurodevelopment

在其他见解中，这项由NSERC资助的研究已经确定，与基因表达相关的自然变异比DNA多态性更常见。从进化的角度来看，这种变异提供了对环境压力的第一道防线，特别是在神经发育期间。此外，我们已经证明，分子技术的进步，可靠地评估这种变异性，现在提供了有效的策略，以调查这种防御在神经发育过程中，这一直是个谜。我们的策略是在期望的时间通过压力源（例如，酒精），并使用RNA-seq和微阵列评估全基因组变化。研究结果使我们得出结论，酒精会在神经发育过程中产生终身的“分子足迹”。此外，这种“足迹”可能是关键行为缺陷的基础，这些行为缺陷通常与神经发育暴露于酒精有关。这项提案将特别关注海马体的分子研究，海马体指导学习和记忆，经常受到产前酒精的影响。* 目标1：评估成年小鼠海马基因表达和DNA甲基化，这些小鼠表现出行为异常，包括神经发育酒精暴露引起的学习/记忆缺陷。*目标二：评估产前酒精暴露诱导的行为和分子景观是否可以通过产后环境富集（阳性）和母体分离（阴性）分别改变（改善或恶化）。本研究以C57 BL/6 J小鼠为动物模型。它开始于两组定时交配（怀孕）的雌性动物的世代。第一组在10%乙醇和水之间进行选择，作为液体（E）的自由选择，第二组仅接收水瓶（W）。怀孕的C57 BL/6 J雌性喜欢（70%）喝10%的酒精，由此产生的后代表现出多种行为影响，包括学习和记忆缺陷。接下来，使来自E和W母亲的所得后代（21天龄）经受三种出生后环境;在自由接触互动玩具和转轮的情况下饲养（富集或积极环境，P）;经受母体分离应激（消极环境，N）和正常饲养（对照，C）。将使用巴恩斯迷宫跟踪代表六个组（EP、EN、EC、WP、WN、WC）的动物的学习和记忆。将使用适当的技术评估这些小鼠的脑皮层的分子足迹。* 研究结果将为DNA甲基化与产前（酒精）和产后环境在学习和记忆进展中的分子相互作用提供新的见解。概述的项目将培训具有神经科学，表观遗传学和涉及基因组学和表观基因组学的现代实验方案专业知识的HQP。这种HQP在后基因组时代是必需的。**

Among other insights, this NSERC funded research has established that the natural variation associated with gene expression is much more common than DNA polymorphism. From evolutionary perspective, this variation offers among the first defence to environmental stresses particularly during neurodevelopment. Further, we have demonstrated that advances in molecular technologies to appraise this variability reliably now offers effective strategies to investigate this defence during neurodevelopment, which has remained enigmatic. Our strategy is to interrupt neurodevelopment at desired time(s) by stressors (eg. alcohol) and evaluate genome-wide changes using RNA-seq and microarrays. The results have allowed us to conclude that alcohol yields a lifelong “molecular footprint” of its encounter during neurodevelopment. Further, this “footprint” may underlie critical behavioral defects often associated with neurodevelopmental exposure to alcohol. This proposal will specifically focus on molecular studies on hippocampus that directs learning and memory often affected by prenatal alcohol. ***Objective 1: To assess hippocampal gene expression and DNA methylation in the adult mice that show behavioral abnormalities including learning/memory deficits caused by neurodevelopmental alcohol exposure.***Objective 2: To assess if prenatal-alcohol-exposure induced behavioral and molecular landscapes could be altered (improved or worsened) by postnatal environmental enrichment (positive) and maternal separation (negative), respectively.****This research will use C57BL/6J mice, as the animal model. It begins with generation of two groups of time-mated (pregnant) females. The first group is given a choice between 10% ethanol and water as the free choice of liquid (E) and the second group receives only water bottle (W). Pregnant C57BL/6J females prefer (70%) to drink 10% alcohol and the resulting progeny shows multiple behavioral effects including learning and memory deficits. Next, the resulting progeny (21 day old) from E and W mothers are subjected to three postnatal environments; raised with free access to interactive toys and running wheels (enrichment or positive environment, P); subject to maternal separation stress (negative environment, N) and normal rearing (control, C). The animals representing six groups (EP, EN, EC, WP, WN, WC) will be followed for learning and memory using Barnes Maze. The hippocampi of such mice will be assessed for molecular footprint using appropriate technologies. ****The results will offer a novel insight in the molecular interplays between DNA methylation and prenatal (alcohol) and postnatal environment in progression of learning and memory. The project as outlined will train HQPs with expertise in neuroscience, epigenetics and modern experimental protocols involving genomics and epigenomics. Such HQPs are needed in this, the post genome era.**