Wildfire Alters DNA Methylation in the Florida Sand Skink

Wildfire is a dynamic event that rapidly alters habitats on an asynchronous timeframe. The occurrence of wildfire, or its suppression, can be stressful to organisms that rely on fire-regulated habitats. Epigenetic mechanisms are induced by the environment and can facilitate organismal response to stress by regulating gene expression. Here, we screened DNA methylation in the federally threatened Florida Sand Skink (Plestiodon reynoldsi) from 13 sites at Archbold Biological Station spanning three categories of time since last fire (TSF): recent (3–6 y), intermediate (7–17 y), and long unburned (18–39 y). We detected thousands of differentially methylated regions in the genome of the Florida Sand Skink among and within TSF categories. We detected a negative relationship between DNA methylation and TSF in this species. Further, we detected an increase in variance of DNA methylation among individuals in recently burned areas, which suggests the Florida Sand Skink uses epigenetic buffering as a response to wildfire stress. The variation in DNA methylation detected among sites within TSF categories indicates that the Florida Sand Skink uses DNA methylation to respond to local conditions, unmeasured in this study, beyond wildfire. Our results indicate that the Florida Sand Skink alters its DNA methylation patterns in response to wildfire and suggest that the changes in DNA methylation facilitate their resilience to wildfire.