The FRT cassette present in the wgKO.FRT.wg.FRT.NRT-wg progenitor allele has been excised, removing the wild-type wg sequence and allowing 'Nrt-wg' (a membrane-tethered, Tag:HA-tagged form of wg in which Tag:M(Nrt) acts as the membrane tethering sequence) to be expressed under the control of endogenous wg regulatory sequences. The loxP cassette (containing a Disc\RFPmCherry.3xP3 marker) present in the progenitor allele is still present downstream of the NRT-wg coding region.
"wg{KO; WT[Body]; NRT-Wg[Discs]}" larvae expressing 'NRT-wg' (a membrane-tethered form of wg) only in imaginal discs (and wild-type wg in other tissues) have been generated by expressing FLPase in the imaginal discs of homozygous wgKO;FRT.wg.FRT.NRT-wg larvae (converting wgKO;FRT.wg.FRT.NRT-wg to wgKO;-FRT.NRT-wg in the discs). These larvae develop at the same rate as controls and eclose at near normal frequency when co-cultured with control siblings. The adult flies are 23% smaller than controls and the wing margin lacks occasional bristles.