Bombyx mori Transcriptome or Gene expression

DNA methylation, as an essential epigenetic modification being found in mammals and plants, has also been implicated to play numerous functional roles in insects. However, the function role of DNA methylation during insect organ or tissue development is far from being clear, due to a lack of experimental manipulation tools to perturb the methylome information under development context. As an effective strategy to inhibit the DNA methylation deposition, we tested the in vivo effects of the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-dC) in the silkworm Bombyx mori, with the aim of investigating the potential functional effect of DNA methylation during silkworm wing development. Here, we show that DNA methylation inhibits the chitin degradation and promotes the wing development in B. mori. This process is primarily mediated by the gene silencing function of DNA methylation in transcriptional level. By downregulating the transcription factor, homeobox protein araucan (Bmara), DNA methylation indirectly suppresses the transcription of chtinase10 (BmCHT10) gene and keeps the structural integrity of the silkworm wings from unwanted chitin degradation, as a consequence, promotes the wing development in Bombyx mori. This study reveals that through the use of DNA methylation inhibitors to induce DNA demethylation in developmental contexts in insects, is help to investigate the potential functional effect of DNA methylation during insect organ or tissue development process, such as wing development. Our results support that transcription repression role of DNA methylation to key wing development-related and chitin metabolism-related genes is a necessary mechanism for insects to keep the proper wing development.