The RMCE cassette in the Mi{MIC}trplMI10071 insertion has been replaced with a 'Double Header' (DH) trapping cassette (contains two independent trapping modules oriented in opposite directions). The cassette is in 'gene-trap' orientation relative to trpl, which is predicted to result in truncation of the trpl coding sequence and expression of the GAL4 driver under the control of endogenous trpl regulatory sequences.