Amino acid replacement: S159D.
UASt regulatory sequences drive expression of the C-terminal 123-179 residues of E(spl)m8-HLH in which the CK2 site has been mutated to a phosphomimetic residue (changes is S159D). This region should thus lack autoinhibitory activity.
Expression of E(spl)123-179.CtD.Scer\UAS in the proneural clusters, under the control of Scer\GAL4455.2 elicits ectopic macrochaeta on the scutellum of 31-54% of flies, with an average penetrance of approximately 41%.
Co-expression of E(spl)S159D.123-179.CtD.Scer\UAS under the control of Scer\GAL4sca-109-68 does not rescue the reduced eye found upon expression of E(spl)SD.Scer\UAS nor the aberrant ommatidial size or patterning.
Co-expression of E(spl)S159D.123-179.CtD.Scer\UAS elicits facet numbers (~650-670) that are indistinguishable from those in Scer\GAL4sca-109-68 E(spl)SD.Scer\UAS flies.
Co-expression of E(spl)S159D.123-179.CtD.Scer\UAS does not restore the scutellar macrochaeta lost in a Scer\GAL4455.2>E(spl)Scer\UAS.cKa background.