Flies carrying Tn10\tetRHsp26.T:Hsim\VP16 and Ras64BV12.Tn10\tetO on tetracycline are viable and fertile, but on normal media flies do not survive. Flies carrying Tn10\tetRYp3.T:Hsim\VP16 and Ras64BV12.Tn10\tetO on tetracycline are viable and fertile, but on normal media female flies do not survive.