Chen Wei, Dong Yuhong, Lin Lianyun, Saqib Hafiz Sohaib Ahmed, Ma Xiaoli, Xu Xuejiao, Zhang Lingling, Jing Xiaodong, Peng Lu, Wang Yue, Vasseur Liette, He Weiyi, You Minsheng
State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China.
Arch Insect Biochem Physiol. 2019 Oct;102(2):e21600. doi: 10.1002/arch.21600. Epub 2019 Jul 22.
DNA methylation exerts extensive impacts on gene expression of various living organisms exposed to environmental variation. However, little is known whether DNA methylation is involved in the host transfer of diamondback moth, Plutella xylostella (L.), a worldwide destructive pest of crucifers. In this study, we found that P. xylostella genome exhibited a relatively low level of DNA methylation on the basis of the CpG O/E prediction and experimental validation. A significant positive linear correlation was observed between the stage-specific expressions of PxDNMT1 and DNA methylation levels (5mC content). Particularly, high levels of DNA methylation and gene expression of PxDNMT1 were observed in eggs and mature females of P. xylostella. After host transfer of P. xylostella from Raphanus sativus to Arabidopsis thaliana, we identified some potential genomic loci that might have changed methylation levels. Using the method of fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP), we also found the corresponding genes primarily involved in neural system and signaling. The expressions of six candidate genes were verified by qRT-PCR. One of the genes, Px009600, might be regulated by a DNA methylation-mediated mechanism in response to host transfer. Our study provides evidence for a functional system of DNA methylation in P. xylostella and its possible role in adaptation during host transfer. Further studies should examine methylation as responsive factors to different host plants and environmental cues in insect pests.
DNA甲基化对暴露于环境变化的各种生物体的基因表达产生广泛影响。然而，对于小菜蛾（Plutella xylostella (L.)）这种十字花科植物的世界性毁灭性害虫，DNA甲基化是否参与其宿主转移尚不清楚。在本研究中，基于CpG O/E预测和实验验证，我们发现小菜蛾基因组的DNA甲基化水平相对较低。观察到PxDNMT1的阶段特异性表达与DNA甲基化水平（5mC含量）之间存在显著的正线性相关。特别是，在小菜蛾的卵和成熟雌虫中观察到高水平的DNA甲基化和PxDNMT1基因表达。在小菜蛾从萝卜转移到拟南芥宿主后，我们鉴定了一些可能发生甲基化水平变化的潜在基因组位点。使用荧光标记的甲基化敏感扩增多态性（F-MSAP）方法，我们还发现相应基因主要参与神经系统和信号传导。通过qRT-PCR验证了六个候选基因的表达。其中一个基因Px009600可能受DNA甲基化介导的机制调控以响应宿主转移。我们的研究为小菜蛾中DNA甲基化的功能系统及其在宿主转移过程中的适应作用提供了证据。进一步的研究应考察甲基化作为害虫对不同宿主植物和环境线索的响应因素。
