D3373: The role of DNA methylation in modulating stress-related gene expression in the Colorado potato beetle (Leptinotarsa decemlineata) under single and combined stress conditions

Tuesday, November 12, 2024

9:00 AM - 5:00 PM MST

Location: Phoenix Convention Center, Exhibit Hall 6, PCC

Presenting Author(s)

Erika M. Bueno (she/her/hers)

Postdoctoral Scholar
University of California
Davis, California

Co-Author(s)

Yolanda H. Chen (she/her/hers)

Professor
University of Vermont
Burlington, Vermont

The ability of agricultural insect pests to rapidly adapt to diverse environmental stressors continues to challenge sustainable pest management. Recent research suggests that exposure to various stressors prompts insects to develop protective responses. Therefore, selection for insecticide tolerance via repeated exposure may shape how insects handle further stress. However, our understanding of how insecticide exposure affects stress responses and molecular mechanisms remains limited. One overlooked area is the role of epigenetic changes in stress responses. Epigenetic modifications, like DNA methylation, can rapidly alter gene expression without changing DNA sequences in response to stressors. This study investigated how insecticide exposure affects DNA methylation patterns in the Colorado potato beetle (Leptinotarsa decemlineata) under different stress conditions. We compared methylation levels of stress-related genes in selected and unselected beetles under four treatments: sublethal imidacloprid LC10 exposure, high temperature (40°C), combined stress (imidacloprid LC10 followed by 40°C), and a control treatment (water at 25°C). Selected beetles showed more pronounced hypomethylation of stress-related genes than unselected beetles. Differential methylation in stress genes occurred across all treatments, indicating alterations compared to controls in both selected and unselected beetles. Moreover, some differentially methylated stress genes, identified in a previous transcriptome study, were upregulated in response to high temperature and combined stress, suggesting DNA methylation might facilitate their transcription. Understanding how epigenetic modifications respond to stressors sheds light on the variable methylation patterns induced by insecticide tolerance selection in resilient insect pests.