When Mrtf^{ΔC.H.Scer\UAS} is expressed under the control of both Scer\GAL4^twi.PG and Scer\GAL4^how-24B together, there is a reduction in ventrodorsal migration of mesoderm cells, which causes a lack of cardiac cells along the dorsal midline of stage 16 embryos. Most dorsal muscles are not formed at stage 16 in these embryos. Expression of Mrtf^{ΔC.H.Scer\UAS} under the control of Scer\GAL4^btl.PS results in defects in the tracheal system in embryos; the dorsal and ganglionic branches are often truncated or missing. Expression of Mrtf^{ΔC.H.Scer\UAS} under the control of Scer\GAL4^da.G32 in embryos results in inhibition of branching in the tracheal system. Defects in mesoderm migration are also seen in these embryos. Expression of Mrtf^{ΔC.H.Scer\UAS} under the control of Scer\GAL4^Bx-MS1096 results in a reduction of intervein tissue in the wing and often results in a failure of the two layers of the wing to fuse completely.