摘要：SummaryThe 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 insectBlattella germanica. In this cockroach, a gene involved in DNA methylation,DNA methyltransferase 1(DNMT1),is expressed in early embryogenesis. In our experiments, RNAi ofDNMT1reduces 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.Graphical AbstractDisplay OmittedHighlights•Blattella germanicahasDNMT1andDNMT3genes, which are expressed in early embryo•DNMT1 depletion reduces DNA methylation levels and impairs early embryo development•Methylated genes are highly expressed and are involved in metabolic processes•High DNA methylation is associated with low expression variabilityDevelopmental Genetics; Molecular Biology
