Ubiquitous expression of dTIP60 in independent fly lines produces a dominant negative lethal effect that can be rescued by an additional copy of wild-type dTIP60.

*p≤0.05.aTest Cross Fly Lines. Ten flies homozygous for either dTip60E431Q or dTip60WT P-element insertions, or control w1118, were mated to seven flies homozygous for the ubiquitous 337-GAL4 driver. For independently derived fly lines dTip60E431 A, B and C the P-element insertions are located on chromosome 3, and for independently derived fly lines dTip60WT A, and C the P-element insertions are located on chromosome 2.bRescue Cross Fly Lines. Four independent rescue lines were generated, each homozygous for dTip60WT (line A or B) on the second chromosome and dTip60E431Q (line A or B) on the third chromosome. Rescue lines are designated as follows: line A is dTip60E431Q B/dTip60WTA, line B is dTip60E431Q B/dTip60WTB, line C is dTip60E431Q A/dTip60WTA, line D is dTip60E431Q A/dTip60WTB. UAS titration control is dTip60E431B/UAS-GFP which is homozygous for UAS-dTip60E431 line B on the third chromosome and UAS-GFP (UAS driven green fluorescent protein) on the second chromosome. Ten homozygous flies for each of the independent rescue fly lines were crossed to seven flies homozygous for the ubiquitous 337-GAL4 driver.cNumber of Surviving Adult Flies. Adult progeny were counted over an eight day period and the total number of surviving flies was scored. Both dTip60E431Q lines reduced viability to 0% that of w1118 control flies. For dTIP60WT line A, there was a significant increase in survivorship when compared to control w1118 flies. All four rescue lines showed significant rescue of the observed lethal phenotype, with rescue lines A and D exhibiting greater than 50% rescue and rescue lines B and C exhibiting 100% rescue. The UAS titration control dTip60E431B/UAS-GFP showed no rescue, indicating that rescue is dependent upon additional dTip60WT protein, and not potential GAL4 titration due to the additional UAS construct. The results are reported as mean ± SD (n = 3); * p≤0.05.