The loxP cassette containing 5xQUAS regulatory sequences has been excised from DroncMV.Tag:V5,C155-Venus, leaving two regulatory modules (an mFRT71 cassette containing 5xlexAop regulatory sequences plus a minimal Hsp70 promoter and an FRT cassette containing 5xUAS regulatory sequences plus a minimal Hsp70 promoter) upstream of of a wild-type Dronc cDNA in which the coding sequence is tagged at the C-terminal end with both Tag:V5 and the C155-Venus split fluorescent fragment.