The RMCE cassette of the Mi{MIC}effMI05507 insertion has been replaced with a FlipFlop cassette in gene-trap (GT) orientation relative to eff. This is expected to truncate the eff protein and to result in the expression of a separate mCherry protein under the control of endogenous eff regulatory sequences.
effMI05507-FF.GT-mCh/effmer4 flies are lethal in the effmer4 lethality complementation test.