PDF(Pubmed)
Abstract：
Environmental conditions experienced within and across generations can impact individual phenotypes via so-called \'epigenetic\' processes. Here we suggest that endocrine signalling acts as a \'sensor\' linking environmental inputs to epigenetic modifications. We focus on thyroid hormone signalling and DNA methylation, but other mechanisms are likely to act in a similar manner. DNA methylation is one of the most important epigenetic mechanisms, which alters gene expression patterns by methylating cytosine bases via DNA methyltransferase enzymes. Thyroid hormone is mechanistically linked to DNA methylation, at least partly by regulating the activity of DNA methyltransferase 3a, which is the principal enzyme that mediates epigenetic responses to environmental change. Thyroid signalling is sensitive to natural and anthropogenic environmental impacts (e.g. light, temperature, endocrine-disrupting pollution), and here we propose that thyroid hormone acts as an environmental sensor to mediate epigenetic modifications. The nexus between thyroid hormone signalling and DNA methylation can integrate multiple environmental signals to modify phenotypes, and coordinate phenotypic plasticity at different time scales, such as within and across generations. These dynamics can have wide-ranging effects on health and fitness of animals, because they influence the time course of phenotypic adjustments and potentially the range of environmental stimuli that can elicit epigenetic responses. This article is part of the theme issue \'Endocrine responses to environmental variation: conceptual approaches and recent developments\'.
摘要：
世代相传的环境条件可以通过所谓的“表观遗传”过程影响个体表型。在这里，我们建议内分泌信号充当“传感器”，将环境输入与表观遗传修饰联系起来。我们专注于甲状腺激素信号和DNA甲基化，但是其他机制可能会以类似的方式发挥作用。DNA甲基化是最重要的表观遗传机制之一,通过DNA甲基转移酶使胞嘧啶碱基甲基化来改变基因表达模式。甲状腺激素与DNA甲基化机制相关,至少部分通过调节DNA甲基转移酶3a的活性，它是介导对环境变化的表观遗传反应的主要酶。甲状腺信号对自然和人为环境影响敏感(例如，温度,内分泌干扰污染)，在这里，我们建议甲状腺激素作为环境传感器来介导表观遗传修饰。甲状腺激素信号和DNA甲基化之间的联系可以整合多种环境信号来修饰表型，并协调不同时间尺度上的表型可塑性，比如代内和代际。这些动态可以对动物的健康和健身产生广泛的影响，因为它们会影响表型调整的时间过程，并可能影响可引起表观遗传反应的环境刺激范围。本文是“内分泌对环境变化的反应：概念方法和最新发展”主题的一部分。
