Comparative transcriptome analysis of Apis mellifera antennae of workers performing different tasks.

Honey bee is a social insect. Its colony is mainly coordinated by the chemical signals such as pheromones produced by queen or brood. Correspondingly, the worker bee developed numerous complicated olfactory sensilla in antennae for detection of these colony chemical signals and nectar/pollen signals in foraging. With the normal development of new emerged workers, young adults (nurse bee) worked in colony at the first 2-3 weeks and then followed by the foraging activity outside of the hive, which give rise to great change of the surrounding chemical signals. However, the olfactory adaption mechanism of worker bee in these processes of behavioral development is still unclear. In this study, we conducted a comprehensive and quantitative analysis of gene expression in Apis mellifera antenna of newly emerged workers, nurses and foragers using transcriptome analysis. Meanwhile, we constructed experimental colonies to collect age-matched samples, which were used to determine whether task is the principal determinant of differential expression. RNA sequencing and quantitative real-time polymerase chain reaction revealed that 6 and 14 genes were closely associated with nurse and forager behaviors, respectively. Furthermore, a broad dynamic range of chemosensory gene families and candidate odorant degrading enzymes were analyzed at different behavior statuses. We firstly reported genes associated with nursing/foraging behavior from antennae and the variations of expression of genes belonging to various olfactory gene families at different development stages. These results not only could contribute to elucidating the relationship between olfactory and behavior-related changes, but also provide a new perspective into the molecular mechanism underlying honey bee division of labor.