A queen among fruitflies

Credit: Masaki Kamakura

The difference between the queen in a honeybee colony and the workers is not a matter of genetics but of nutrition: larvae that consume royal jelly become queens. The active royal-jelly ingredient has long remained elusive, but is now identified as royalactin, a previously known protein that exhibits epidermal growth factor (EGFR)-like effects on rat hepatocytes. Surprisingly, royalactin also induces queen-like phenotypes in the fruitfly Drosophila melanogaster, increasing body size and ovary development through an EGFR-mediated signalling pathway.