Behavioral and transcriptomic responses of wild least horseshoe bats to artificial light.

Artificial light has altered nighttime environments, jeopardizing the fitness of organisms. While many nocturnal animals avoid artificial light, the molecular mechanisms behind this phenomenon remain elusive. This study aimed to explore the behavioral and transcriptomic responses of least horseshoe bats (Rhinolophus pusillus) to artificial light. We manipulated three lighting conditions (i.e., dark control, white light, and green light) inside bat roost. We assessed behavioral responses and gene expressions in the adrenal gland-kidney complexes and brains of bats. Our analyses showed that white and green light caused a decline in bat flight activity and the number of echolocation vocalizations per pass. White and green light activated gene expressions responsible for glucocorticoid synthesis and metabolism. The flight activity of bats was negatively associated with expression levels of ADCY8 and SERPINA6 genes. These findings imply that gene expressions involved in glucocorticoid signaling pathways affect light aversion in wild bats.