DNA methylation refers to the addition of cytosine residues in a CpG context (5′‐cytosine‐phosphate‐guanine‐3′). As one of the most common mechanisms of epigenetic modification, it plays a crucial role in regulating gene expression and in a diverse range of biological processes across all multicellular organisms. The relationship between temperature and DNA methylation and how it acts on the adaptability of migratory insects remain unknown. In the present work, a 5,496 bp full‐length complementary DNA encoding 1,436 amino acids (named MsDnmt1) was cloned from the devastating migratory pest oriental armyworm, Mythimna separata Walker. The protein shares 36.8–84.4% identity with other insect Dnmt1 isoforms. Spatial and temporal expression analysis revealed that MsDnmt1 was highly expressed in adult stages and head tissue. The changing temperature decreased the expression of MsDnmt1 in both high and low temperature condition. Besides, we found that M. separata exhibited the shortest duration time from the last instar to pupae under 36°C environment when injected with DNA methylation inhibitor. Therefore, our data highlight a potential role for DNA methylation in thermal resistance, which help us to understand the biological role adaptability and colonization of migratory pest in various environments.

中文翻译：

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DNA甲基转移酶1的分子特征及其在粘虫Mythimna separata Walker温度变化中的作用。

DNA甲基化是指在CpG上下文中添加胞嘧啶残基（5'-胞嘧啶-磷酸-鸟嘌呤-3'）。作为表观遗传修饰的最常见机制之一，它在调节基因表达以及所有多细胞生物的多种生物学过程中都起着至关重要的作用。温度和DNA甲基化之间的关系以及它如何影响迁徙昆虫的适应性仍然未知。在目前的工作中，从具有毁灭性的迁徙性害虫东方粘虫Mythimna separata Walker中克隆了一个5496 bp的全长互补DNA，编码1,436个氨基酸（称为MsDnmt1）。该蛋白与其他昆虫Dnmt1同工型具有36.8–84.4％的同一性。时空表达分析显示MsDnmt1在成年阶段和头部组织中高度表达。温度的变化降低了MsDnmt1在高温和低温条件下的表达。此外，我们发现，在36℃的环境下，注射DNA甲基化抑制剂后，分离的分枝杆菌表现出从最后一龄到to的最短时间。因此，我们的数据突出了DNA甲基化在耐热性中的潜在作用，这有助于我们了解各种环境中迁徙性害虫的生物学作用适应性和定殖。