Intersexual differences in the number of genes differentially expressed in wild mammals in response to predation risk.

Predation is a psychological stressor in prey animals. Besides direct killing and consumption by predators, the perception of predation risk indirectly influence prey population behavior, dynamics and physiology. Few studies identified the transcriptomic response associated with predator presence/abundance in natural populations and uncontrolled settings. However, to our knowledge, intersexual differences in the number of genes whose expression change in response to high predation risk have not been previously reported in wild mammals. Here, by using publicly available gene expression data in wild yellow-bellied marmots (Marmota flaviventer), we found that the number of differentially expressed genes in response to predator stress is higher in female marmots (n = 516) than males (n = 387). Only a small percentage of these differentially expressed genes (n = 36) are shared between the sexes, and that the most of the differentially expressed genes are expressed in a sex-specific manner in response to predation stress. Overall, our results provide new insight into sex-specific variation in gene expression changes in wild mammals under high predation risk.