Meeting Abstract
Reversible acclimation represents a universal strategy among organisms that reduces stress from the environment. Dehydration stress threatens terrestrial taxa by directly reducing performance or constraining durations of foraging and reproductive activities. Organisms can avoid dehydration stress by reducing water loss rates; however, we know very little on the capacities of organisms to adjust water loss rates and the environmental cues that elicit acclimation of water loss rates. We conducted an acclimation experiment to evaluate the capacity of a terrestrial salamander (Plethodon metcalfi) to adjust rates of water loss in response to cycling temperature and humidity treatments as cues for acclimation. Our experimental design controlled for the evaporative demand of the air by adjusting relative humidities with the cycling temperatures to explicitly test temperature and humidity as cues for acclimation. Then, we monitored changes in skin resistance to water loss over the course of four weeks in the acclimation study using a flow through system. After the final measurements, we sacrificed the individuals and extracted total RNA from skin tissue. From these samples, we constructed a de novo transcriptome and performed a differential gene expression analysis. The experiment revealed that salamanders acclimated to temperature, and individuals exhibited variation in acclimation response in which individuals either lowered water loss rates during the experiment or they maintained low water loss rates throughout the entire experiment. Our differential gene expression analysis identifies potential networks of genes that explain variation in acclimation capacities. These potential regulatory networks might provide a basis for predicting acclimation responses to environmental stressors, such as warming temperatures.
