Torpor-responsive expression of novel microRNA regulating metabolism and other cellular pathways in the thirteen-lined ground squirrel, Ictidomys tridecemlineatus.

Research has demonstrated the importance of microRNA in cold-tolerant animals, including their dynamic regulation throughout mammalian hibernation. In this study, we used small RNA sequencing and bioinformatic methods to identify novel microRNA regulating gene expression during hibernation in thirteen-lined ground squirrels, Ictidomys tridecemlineatus. A group of 17 novel microRNA was identified, and their relative expression was quantitated using real-time quantitative polymerase chain reaction in liver, skeletal muscle, and heart tissues over four experimental conditions that represent the torpor-arousal cycle. Predicted mRNA targets of these novel microRNA were found to be enriched in biological processes known to be regulated during hibernation, such as lipid metabolism, ion-transport ATPases, and various cellular signaling cascades. This study provides an analysis of several novel microRNA that may be crucial to adaptation during hibernation.