A knock-in allele, in which a mScarlet tag is inserted after codon 485 (this is after the last processing site, and should result in all dpp mature ligands being tagged). The mutagenesis method took advantage of two transposable elements (Mi{MIC}dppMI03752 and PBac{RB}e00178) in the dpp locus, and the resulting knock-in allele has a single FRT site, plus a w+mC marker (from PBac{RB}e00178), downstream of the dpp 3'UTR.