It’s getting hot in here: Detecting a thermosensory gene in honeybees

Ambient temperature is critical to an insect’s survival and limits a species’ ability to occupy different habitats. Social insects such as the Western honeybee (Apis mellifera ) thrive in a range of environments, building nest-structures that protect their inhabitants while providing ideal conditions for developing brood. As ambient temperatures increase, honeybee workers also display thermoregulatory fanning behavior at nest entrances or near the brood to maintain temperatures of ~35°C. Earlier studies have hypothesised individual response thresholds determining who fans and when, but workers must be able to detect temperature changes first so they can respond in a timely manner. Ion channels of the subfamily TRPA (Transient receptor potential A) are implicated in detection of temperature changes across taxa. An equivalent Hymenoptera-specific gene, AmHsTRPA is found in A. mellifera. Activating at ~34°C, AmHsTRPA may play a vital role in determining the response threshold of fanning workers, but few studies have investigated this possibility. To ascertain how a bee perceives temperature change, we test the expression of AmHsTRPA in different parts of the head, the thorax and the abdomen of workers. Such a test can identify specific targets where signals should be first detected to mount an appropriate fanning response. Additionally, since this gene neofunctionalised to take on both thermosensory and chemosensory functions, different body parts may be sensitive to different cues. We can use insights from our study to functionally test the effect of AmHSTRPA on honeybee behavior especially in the face of human-induced thermal and chemical changes to the environment.