Unmasking the Epigenetic Landscape of Freeze Tolerance in the Grey Tree Frog

For the breadth of the winter, Dryophytes versicolor can survive full body freezing utilizing a phenomenon known as metabolic rate depression (MRD). Differentially expressed miRNA regulate translation through mRNA targets and prove to be a promising candidate for the study of stress tolerance. Additional epigenetic transcriptional control on gene expression, such as histone methylation and acetylation, also implement a balance between permissive and restricted chromatin as required to endure freezing. The current study utilizes next-generation sequencing and bioinformatic analyses to characterize changes in the microRNAome of D. versicolor muscle tissue in response to freezing. Adding to this, the interplay between histone lysine methyl and acetyl transferases (HKMTs, HATs), as well as the abundance of various acetyl-lysine and methyl-lysine moieties on histone H3 and H4 were examined. This study highlights the regulative role played by miRNA and histone modifications on the overall repression of energy-expensive processes during freezing in muscle tissue.