A 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, wingless is thought to be expressed in developing campaniform sensillum 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, express wingless, as indicated by in situ hybridization 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 unique wingless expression pattern by analyzing gene regulation in dome cells and socket cells.

圆点果蝇 Drosophila guttifera在其翅膀上具有独特的色素沉着模式，并被用作探索新特性进化获得机制的 evo-devo 研究的模型。在该物种中，一种形态发生素编码基因wingless在物种特异性位置表达并诱导独特的色素沉着模式。为了在翼脉上产生一些色素沉着点，无翅被认为在发育中的钟状感器细胞中表达，但未知四种细胞类型中的哪一种表达无翅。在这里我们展示了两种细胞类型，圆顶细胞和插座细胞，表达无翅，如原位杂交和免疫组织化学所示。这是一个独特的案例，其中非神经元 SOP（感觉器官前体）后代细胞产生 Wingless 作为色素沉着模式形成的诱导剂。我们的发现通过分析圆顶细胞和窝细胞中的基因调控，为阐明独特的无翼表达模式的进化获得机制开辟了道路。