3xP3 regulatory sequences are fused upstream of three tandem copies of mTagBFP2. UASt sequences are present downstream of the 3xmTagBFP2 coding sequence (as part of the Dcr-2UAS.cSa allele present in P{3xP3-3XTagBFP2.UAS-Dcr-2}); these UASt sequences also influence expression of the 3xmTagBFP2 coding sequence, so that 3xmTagBFP2 is expressed under the control of both 3xP3 and UASt sequences in the P{3xP3-3XTagBFP2.UAS-Dcr-2} transgene.