Molecular Responses to Temperature Changes Across Timescales in the Madagascar Ground Gecko (Paroedura picta).

Short-term responses to temperature stress, such as heat waves and long-term acclimation to temperature changes, including seasonal shifts, are expected to be mediated by distinct molecular pathways. However, in ectotherms, such as reptiles, the effects of exposure duration on molecular responses to temperature change remain unclear. In this study, we investigated temperature-induced molecular changes across distinct timescales in a newly established reptilian model species, the Madagascar ground gecko (Paroedura picta). To determine temperature-responsive phenotypes and assess phenotypic plasticity under long-term temperature changes, we compared thermal traits in individuals acclimated to 25°C and 30°C for more than 30 days. We found significant differences in the critical thermal minimum and maximum as well as sprint speed between the two groups. We then employed RNA sequencing and the assay for transposase-accessible chromatin using sequencing to analyse gene expression, splicing and chromatin states across multiple temperature conditions and durations. Results revealed that abrupt temperature shifts activated known heat stress pathways, whereas prolonged temperature acclimation altered immune function. In the liver, the predicted occupancy of some transcription factors diverged between short- and long-term temperature stimuli. These findings indicate that transient temperature stress responses and long-term temperature acclimation in P. picta involve distinct molecular mechanisms.