Characterization and expression analysis of the foraging gene in the Formosan subterranean termite, Coptotermes formosanus

Foraging is a critical activity for resource acquisition in eusocial insects. In subterranean termites, workers perform foraging through underground tunnel systems. This behavior is influenced by both environmental and genetic factors. The foraging (for) gene regulates food related behaviors in a wide range of organisms, including solitary insects like Drosophila and eusocial species such as the honey bee. However, its function in termites remains poorly understood. In this study, we characterized the full-length sequence of the for gene in the Formosan subterranean termite, Coptotermes formosanus. Sequence analysis and phylogenetic comparisons with for orthologs from other insects revealed strong conservation, suggesting a functionally important and evolutionarily conserved role. We examined for expression across developmental stages, egg, larva, worker, nymph, pre-soldier, and male and female alates, to assess temporal variation. Tissue specific expression in workers was evaluated by analyzing the antennae, brain, head capsule, gut, and carcass. The for gene expression was highest in female alates, followed by workers and larvae. In worker tissues, the carcass showed the highest expression, followed by the gut, while the brain exhibited the lowest levels. These findings suggest that for may have pleiotropic roles beyond foraging behavior. Additionally, we assessed for expression under different environmental (20 °C and 30 °C; constant light vs. dark) and social (varying soldier proportions) conditions. Expression profiles revealed that for responds to both environmental and social cues, providing new insights into its regulatory role in foraging and potentially other physiological processes in C. formosanus.