ABSTRACT

It is increasingly recognized that epigenetic mechanisms play a key role in acclimatization and adaptation to thermal stress in invertebrates. DNA methylation and its response to temperature variation has been poorly studied in insects. Here, we investigated DNA methylation and hydroxymethylation patterns in the viviparous cockroach Diploptera punctata at a global and gene specific level in response to variation in temperature. We specifically studied methylation percentage in the heat shock protein 70 (Hsp70), whose function is linked to thermal plasticity and resistance. We found high levels of DNA methylation in several tissues but only low levels of DNA hydroxymethylation in the brain. Hsp70 methylation patterns showed significant differences in response to temperature. We further found that global DNA methylation variation was considerably lower at 28°C compared to higher or lower temperatures, which may be indicative of the optimal temperature for this species. Our results demonstrate that DNA methylation could provide a mechanism for insects to dynamically respond to changing temperature conditions in their environment.

摘要

人们越来越认识到，表观遗传机制在无脊椎动物的驯化和适应热应激中起关键作用。DNA甲基化及其对温度变化的反应在昆虫中的研究很少。在这里，我们研究了胎生蟑螂Diploptera punctata的 DNA 甲基化和羟甲基化模式。在全球和基因特定的水平上响应温度的变化。我们专门研究了热休克蛋白 70 (Hsp70) 中的甲基化百分比，其功能与热可塑性和抗性有关。我们在几个组织中发现了高水平的 DNA 甲基化，但在大脑中只有低水平的 DNA 羟甲基化。Hsp70 甲基化模式显示出对温度的显着差异。我们进一步发现，与更高或更低的温度相比，28°C 的全球 DNA 甲基化变异要低得多，这可能表明该物种的最佳温度。我们的研究结果表明，DNA 甲基化可以为昆虫动态响应环境中不断变化的温度条件提供一种机制。