Non-CG DNA methylation marks the transition from pupa to adult in Helicoverpa armigera

• Published in: Insect molecular biology Vol. 33; no. 5; pp. 493 - 502
• Main Authors: Royle, Jack W, Hurwood, David, Sadowski, Pawel, Dudley, Kevin J
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.10.2024
• Subjects: Agricultural practices; Bisulfite; Chromatin remodeling; Deoxyribonucleic acid; DNA; DNA methylation; Epigenetics; Gene expression; Gene sequencing; Genes; Hedgehog protein; Helicoverpa armigera; Insects; Integrated pest management; Kinases; Larvae; MAP kinase; Mass spectrometry; Mass spectroscopy; Pest control; Pests; Proteins; Pupae; Signal transduction; targeted mass spectrometry; Helicoverpa armigera; epigenetics; non‐CG methylation; whole‐genome bisulfite sequencing
• ISSN: 0962-1075; 1365-2583; 1365-2583
• DOI: 10.1111/imb.12917

DNA methylation in insects is generally low in abundance, and its role is not well understood. It is often localised in protein coding regions and associated with the expression of 'housekeeping' genes. Few studies have explored DNA methylation dynamics during lifecycle stage transitions in holometabolous (metamorphosing) insects. Using targeted mass spectrometry, we have found a significant difference in global DNA methylation levels between larvae, pupae and adults of Helicoverpa armigera (Lepidoptera: Noctuidae) Hübner, a polyphagous pest of agricultural importance. Whole-genome bisulfite sequencing confirmed these observations and pointed to non-CG context being the primary explanation for the difference observed between pupa and adult. Non-CG methylation was enriched in genes specific to various signalling pathways (Hippo signalling, Hedgehog signalling and mitogen-activated protein kinase (MAPK) signalling) and ATP-dependent chromatin remodelling. Understanding the function of this epigenetic mark could be a target in future studies focusing on integrated pest management.