DNA methylation patterns respond to thermal stress in the viviparous cockroachDiploptera punctata

It is increasingly recognized that epigenetic mechanisms play a key role in acclimatization and adaptation to thermal stress in invertebrates. DNA methylation and its response to temperature variation has been poorly studied in insects. Here, we investigated DNA methylation and hydroxymethylation patterns in the viviparous cockroachDiploptera punctataat a global and gene specific level in response to variation in temperature. We specifically studied methylation percentage in the heat shock protein 70 (Hsp70), whose function is linked to thermal plasticity and resistance. We found high levels of DNA methylation in several tissues but only low levels of DNA hydroxymethylation in the brain. Hsp70 methylation patterns showed significant differences in response to temperature. We further found that global DNA methylation variation was considerably lower at 28 degrees C compared to higher or lower temperatures, which may be indicative of the optimal temperature for this species. Our results demonstrate that DNA methylation could provide a mechanism for insects to dynamically respond to changing temperature conditions in their environment.

Automated summary

DNA methylation and hydroxymethylation patterns in response to temperature variation were investigated in the viviparous cockroach Diploptera punctata, with high levels of DNA methylation in several tissues but low levels of DNA hydroxymethylation in the brain. Methylation patterns of the heat shock protein 70 (Hsp70) showed significant differences in response to temperature, with global DNA methylation variation considerably lower at 28 degrees C compared to other temperatures, indicating a potential optimal temperature for this species. The results suggest that DNA methylation may provide a mechanism for insects to respond dynamically to changing temperature conditions in their environment.