Polytene chromosomes normal.
Less than 5% of dor4 hk11 double mutants eclose into adults, with the lethal phase occurring in the late pupal stage. dor4 hk11 double mutants have a decreased number of boutons and are indistinguishable from dor4 mutants alone. However, in the presence of a dor duplication, such as Dp(1;Y)1E, the size of the dor4 hk11 double mutant synapse is like hk11 mutants.
The eye colour phenotype of dor4 flies is rescued by dor1-1002.Scer\UAS or dor400-1002.Scer\UAS expressed under the control of Scer\GAL4GMR.PF. The eye colour phenotype of dor4 flies is not rescued by dorΔ401-800.Scer\UAS or dor1-802.Scer\UAS expressed under the control of Scer\GAL4GMR.PF, and the level of eye pigmentation in these flies is further reduced compared to dor4 single mutant flies.