Molecular characterization of foraging gene in the Formosan subterranean termite, Coptotermes formosanus (Blattodea: Rhinotermitidae)

Collective foraging is an essential activity for resource acquisition in eusocial insects. In subterranean termites, workers are the foragers, and the foraging activity is conducted in underground tunnels. Foraging behavior is mediated by both environmental and genetic factors. The foraging (for) gene regulates food-related behaviors in diverse organisms, including solitary insects such as Drosophila and social insects such as the honey bee. However, this gene remains poorly characterized in termites. In this study, we evaluated expression levels of for gene in different developmental stages and tissues of the Formosan subterranean termite, Coptotermes formosanus. To determine temporal changes in for gene expression, egg, larva, worker, nymph, pre-soldier, male alate and female alate were examined. Antennae, brain, head capsule, gut and carcass of workers were dissected to examine the tissue-specific expression pattern. We found that, expression of for gene was the highest in female alate, followed by worker and larvae. In worker tissues, the highest expression was found in carcass, followed by gut. Surprisingly, the lowest expression of for was observed in brain samples. This suggests that for might be pleiotropic and regulating functions other than foraging. In addition, we assessed the expression of for in termites exposed to different environmental conditions. Termites exposed to different temperatures (20 °C and 30 °C) and photoperiods (24h:0h and 0h:24h light-dark cycles) were sampled for gene expression analyses. Expression profiles of for gene provides insights into potential roles of this gene in foraging activity of C. formosanus.