Expression of Ser^DN.Scer\UAS under the control of Scer\GAL4^ato.3.6 results in a significant increase in the number of medulla axons compared to wild type.

Expression of Ser^DN.Scer\UAS under the control of Scer\GAL4^tin.CΔ4 post-development (by co-expression of Scer\GAL80^ts.αTub84B, inactivated post-embryonically by shifting the flies to 26[o]C) results in deterioration of cardiac function, and this can be corrected by a second temperature shift back to 18[o]C. Animals show dilated cardiomyopathy, with enlarged end-diastolic and end-systolic dimensions, and impaired fractional shortening.

Eye-antennal discs, in which Ser^DN.Scer\UAS is expressed under the control of either Scer\GAL4^ey.PB or Scer\GAL4^ey.PH, display small or no eye fields by mid- to late-L3 and some discs display full or partial double antennal domains. This leads to adult flies lacking eyes and sometimes displaying double antennae. The double antennae appear to originate from a duplication of the antenna primordium, rather than an eye-to-antenna transformation. Expression of Ser^DN.Scer\UAS, under the control of either Scer\GAL4^ey.PB or Scer\GAL4^ey.PH, in mid-late L2 eye discs results in a severe suppression of cell division, shown by a decreased number of mitotic cells.

Expression of Ser^DN.Scer\UAS under the control of Scer\GAL4^ey.PB can result in homeotic transformation of the eye to antenna at 25^oC (no transformation is seen at 18^oC). Temperature shift experiments show that the phenocritical period for the homeotic transformation is chiefly within the latter half of the second larval stage. Expression of Ser^DN.Scer\UAS under the control of Scer\GAL4^ey.PB in the third larval stage (using temperature shifts) results in defects in regulation of the morphogenetic furrow.

Expression of Ser^DN.Scer\UAS under the control of Scer\GAL4^dpp.blk1 inhibits furrow reincarnation but not birth in the eye disc.