EcollacZ^{Rbfox1-EN403-lacZ} is expressed in the same pattern as Rbfox1. EcollacZ^{Rbfox1-EN403-lacZ} is expressed in all imaginal discs. In the wing disc, expression is observed in the wing pouch and in myoblast cells (adepithelial cells) of the presumptive notum. EcollacZ^{Rbfox1-EN403-lacZ} is expressed in the central regions of the antennal and leg discs, and in cells posterior to the morphogenetic furrow in the eye disc. EcollacZ^{Rbfox1-EN403-lacZ} is also expressed in the CNS, PNS, and pericardial cells starting at the extended germ band stages of embryogenesis through larval stages, and in larval trachea and muscle cells.