starfish in water

Thermal versus predator stress: snails can tell the difference

Organisms living in the intertidal zone must deal with a complex combination of stressors, such as thermal stress during low tide, as well as stress due to fear of predators. Just as stressed humans behave differently, stress causes behavioral, morphological and even metabolic changes in intertidal organisms as well. Recent techonological advances have allowed scientists to investigate stress responses on a molecular level, by measuring how genes and proteins are expressed during stressful versus non-stressful conditions, and while several studies have documented genetic responses to thermal stress, few have measured reaction to stress from fear of predators.

To fill this gap in knowledge, a team of researchers including former Three Seas student Nathaniel Chu, MSC graduate student Stefan Kaluziak, Director Geoff Trussell and Associate Professor Steve Vollmer used next-generation RNA sequencing to document gene expression in the intertidal snail Nucella lapilus, in response to thermal stress and predation risk. The results of their study were published recently in the journal Molecular Ecology.

The researchers found that, like other intertidal species, N. lapilus displays distinct changes in gene expression in response to thermal stress, including production of heat-shock proteins that protect the body from thermal damage. However, stress from a crab predator induced few changes in gene expression, indicating that thermal and predation stress pose distinct challenges for this intertidal snail. These results enhance understanding of genetic response to stress and indicate that responses to biotic stress such as predation risk might be more complex and less uniform across species than responses to abiotic thermal stress.