The color pattern inducing genewinglessis expressed in specific cell types of campaniform sensilla of a polka-dotted fruit fly,Drosophila guttifera

Abstract

AbstractA polka-dotted fruit fly,Drosophila guttifera,has a unique pigmentation pattern on its wings and is used as a model for evo-devo studies exploring the mechanism of evolutionary gain of novel traits. In this species, a morphogen-encoding gene,wingless, is expressed in species-specific positions and induces a unique pigmentation pattern. To produce some of the pigmentation spots on wing veins,winglessis thought to be expressed in developing campaniform sensilla cells, but it was unknown which of the four cell types there express(es)wingless. Here we show that two of the cell types, dome cells and socket cells, expresswingless, as indicated byin situhybridization together with immunohistochemistry. This is a unique case in which non-neuronal SOP (sensory organ precursor) progeny cells produce Wingless as an inducer of pigmentation pattern formation. Our finding opens a path to clarifying the mechanism of evolutionary gain of a uniquewinglessexpression pattern by analyzing gene regulation in dome cells and socket cells.