The RMCE cassette of the Mi{MIC}ShalMI00446 insertion has been replaced with a FlpTag conditional tagging cassette that is inserted in the opposite orientation to the direction of Shal transcription. In the absence of FLP, the Shal gene is not tagged, but in the presence of FLP recombinase, the FlpTag cassette is stably inverted, resulting in conditional tagging of the Shal gene.