Meeting Abstract
Thermal stress affects organisms on multiple levels of biological organization, from cellular stress to behavioural thermoregulation. Typically, an individual’s responses to cold and heat stress at the cellular level are divergent; however, their behavioral responses may be similar at thermal extremes. Astrangia poculata is a temperate stony coral that lives subtidally on the East coast of the United States and experiences large temperature ranges throughout the year (3 oC to 25 oC). To examine how A. poculata responds to these thermal extremes across behavioral and molecular scales, we conducted two common garden thermal stress experiments (cold, heat) and monitored behavioral responses to food stimuli and measured genome-wide gene expression. Behaviorally, both cold and heat stress caused polyp retraction and individuals appeared to enter quiescent-like states. In contrast, gene expression profiling across the two experiments revealed functionally divergent responses to the two thermal extremes at the molecular level, relative to control conditions. We found that the molecular underpinnings behind the quiescent-like behaviors observed under both heat and cold stress were associated with distinct functional pathways, and a wide range of genes were identified as core thermal response genes within each stressor. These results illustrate how identical behavioural responses can be underscored by significantly different mechanisms and highlight how a temperate stony coral can physiologically withstand such a broad range of ambient environmental temperatures.
