Epigenetic regulatory mechanisms during neurodevelopment

在其他见解中，这项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个防御，特别是在神经发育过程中。此外，我们已经证明，分子技术的进步可靠地评估了这种变异性，现在为研究神经发育过程中的这种防御提供了有效的策略，这仍然是一个谜。我们的策略是在需要的时间通过压力源中断神经发育。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，酒精在神经发育过程中会产生终生的“分子足迹”。此外，这种“足迹”可能是关键行为缺陷的基础，通常与神经发育暴露于酒精有关。这一建议将特别侧重于海马体的分子研究，海马体指导经常受到产前酒精影响的学习和记忆。***目的1：评估由神经发育性酒精暴露引起的行为异常（包括学习/记忆缺陷）的成年小鼠海马基因表达和DNA甲基化。***目的2：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）和母亲分离（阴性）分别改变（改善或恶化）。****本研究将以C57BL/6J小鼠为动物模型。它开始于两组时间交配（怀孕）的雌性。第一组被给予10%乙醇和水作为自由选择的液体(E)，第二组只得到水瓶(W)。怀孕的C57BL/6J雌性更喜欢（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，E和W母鼠的后代（21日龄）受到三种产后环境的影响；长大后可以自由使用互动玩具和滚轮（丰富或积极的环境，P）；母性分离应激（阴性环境，N）和正常饲养（对照，C）。采用巴恩斯迷宫法对6组（EP、EN、EC、WP、WN、WC）动物进行学习记忆跟踪。这些小鼠的海马体将使用适当的技术来评估分子足迹。****该结果将为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。该项目将培养具有神经科学、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HQPs。在后基因组时代，这样的HQPs是需要的

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.**