A 1.86-kb mpeg1 promoter fragment drives transient transgene expression in macrophages. (A) Transient mosaic transgene expression in embryos injected with tol2-flanked Tg(mpeg1:mCherry) (i) and Tg(mpeg1:EGFP) (ii) DNA constructs into Tg(lyz:EGFP) and Tg(lyz:dsRed) transgenic backgrounds, respectively. The experiment was conducted on Tg(lyz:EGFP) and Tg(lyz:dsRed) embryos to provide comparison and nonoverlap of expression with neutrophils. (B) Transgene expression in F0 adults injected with tol2-flanked Tg(mpeg1:mCherry) (i,iii) and Tg(mpeg1:EGFP) (ii) DNA constructs. (iii) Tg(mpeg1:mCherry) was introduced onto the Tg(mpx:EGFP) background to provide comparison and nonoverlap of expression with neutrophils. (C) Transient transgene expression resulting from delivery of a tol2-flanked Tg(mpeg1:Gal4-VP16) construct into Tg(UAS:Kaede) embryos results in expression of Kaede in dispersed cells (i) that migrate in response to wounding (tail transection) (ii-v). Time: hours post injury (hpi). (D) Delivery of tol2-flanked Tg(mpeg1:Gal4-VP16) into Tg(UAS:Kaede/lyz:dsRed) embryos allows comparison of macrophage (green, arrowheads) and neutrophil populations (red) migrating in response to wounding (tail transection). Time: hours post injury (hpi).