Dramatic changes in patterning gene expression during metamorphosis are associated with the formation of a feather-like antenna by the silk moth, Bombyx mori

► Morphological evolution of the branched pheromone-receptive antenna of the silk moth. ► Morphogenesis of branches via localized cell proliferation and ubiquitous cell death. ► Antennal patterning genes show the pattern conserved among insects in early stages. ► Dramatic change to the pattern prefiguring the branches occurs during metamorphosis. ► A novel regulatory circuit of antennal patterning was acquired during evolution.