The transposon containing an unspecified hybrid actin promoter driving expression of red fluorescent protein (RFP) flanked by piggyBac-specific left and right terminal sequences was co-injected with a piggyBac-containing transgene to mobilize the transposon. The transposon inserted in inverse orientation into the first intron at nucleotide 74379378. Transcript levels are reduced by 50% in homozygous embryos at E15.5. (J:324705)