The influence of DNA methylation on gene behavior and its consequent phenotypic effects appear to be very important, but the details are not well understood. Insects offer a diversity of DNA methylation modes, making them an excellent lineage for comparative analyses. However, functional studies have tended to focus on quite specialized holometabolan species, such as wasps, bees, beetles, and flies. Here, we have studied DNA methylation in the hemimetabolan insect Blattella germanica. In this cockroach, a gene involved in DNA methylation, DNA methyltransferase 1 (DNMT1), is expressed in early embryogenesis. In our experiments, RNAi of DNMT1 reduces DNA methylation and impairs blastoderm formation. Using reduced representation bisulfite sequencing and transcriptome analyses, we observed that methylated genes are associated with metabolism and are highly expressed, whereas unmethylated genes are related to signaling and show low expression. Moreover, methylated genes show greater expression change and less expression variability than unmethylated genes.

DNA甲基化对基因行为的影响及其随之而来的表型效应似乎非常重要，但细节尚不清楚。昆虫具有多种 DNA 甲基化模式，使其成为比较分析的绝佳谱系。然而，功能研究往往集中于相当专门的全变态物种，如黄蜂、蜜蜂、甲虫和苍蝇。在这里，我们研究了半变态昆虫德国小蠊的 DNA 甲基化。在这种蟑螂中，参与 DNA 甲基化的基因DNA 甲基转移酶 1 ( DNMT1 )在早期胚胎发生过程中表达。在我们的实验中， DNMT1的 RNAi 减少了 DNA 甲基化并损害胚盘形成。使用简化代表性亚硫酸氢盐测序和转录组分析，我们观察到甲基化基因与代谢相关并且高表达，而非甲基化基因与信号传导相关并且表现出低表达。此外，与未甲基化基因相比，甲基化基因表现出更大的表达变化和更小的表达变异性。