Dp(3;3)TplJE19 heterozygous flies (carrying three copies of Tpl) die in the first instar larvae stage. Before death, the midgut turns brown (and is the first tissue to die), and tracheal development is abnormal. This is accompanied by more widespread cell death, and then the tracheae appear to break up and turn brown. Soon thereafter, the entire animal dies. These flies are also developmentally-retarded (they exhibit the first-instar phenotype at a time when the wild-type would have already moulted to the second instar stage).
Su(Tpl)10 entirely eliminates the abnormalities and death caused by Tpl trisomy (such as Dp(3;3)Tpl or Dp(3;3)TplJE19 flies), and results in viable, fertile adults.
