The FRT cassette has been excised, allowing the Act5C promoter to drive expression of the full-length fz open reading frame. The coding sequence is tagged at the C-terminal end with EYFP.

The degree of rescue of wing hair polarity defects due to fz¹⁵/fz²⁵, by fz^{Act5C.T:Avic\GFP-EYFP} depends on the timing after puparium formation (APF) of its generation from fz^{Act5C.Scer\FRT.T:Avic\GFP-EYFP} using Scer\FLP1^hs.PG : heat shock prior to 6hrs APF gives complete rescue; heat shock at 6 hours APF leads to weak polarity defects; progressively stronger polarity defects are seen with successively later heat shocks administered after 6hrs APF; heat shocks from 27 hours APF produce progressively weaker phenotypes, and those after 31 hours APF produce polarity phenotypes identical to fz¹⁵/fz²⁵ alone. The strong wing hair polarity phenotypes seen with heat shocks after 6 and before 24 hours APF, resemble those due to ds^33k/ds^UAO71, in terms of overall pattern, and in the tendency of wing hairs to form at edges, rather than away from the edge, as in fz¹⁵/fz²⁵ without rescue. When fz^{Act5C.T:Avic\GFP-EYFP} is generated from fz^{Act5C.Scer\FRT.T:Avic\GFP-EYFP} using Scer\FLP1^hs.PG activity induced at 12 hours after puparium formation (APF), largely rescues wing hair polarity defects due to fz¹⁹/fz¹⁵. The degree of rescue of ommatidial polarity defects due to fz¹⁵/fz²⁵, by fz^{Act5C.T:Avic\GFP-EYFP} depends on the timing after egg laying of its induction from fz^{Act5C.Scer\FRT.T:Avic\GFP-EYFP} using Scer\FLP1^hs.PG : Induction of the transgene prior to 96 hr after egg laying (AEL) results in complete rescue of ommatidial polarity defects. Induction between 96 and 104 hr AEL produces some flies with a distinctive polarity phenotype in which the dorsoventral polarity of ommatidia is partially randomized, a phenotype much more like that due to ds^38k/ds^UAO71 than to fz¹⁵/fz²⁵. With a slightly later induction (104-112 hr AEL), most individuals show this phenotype. Finally, expression of the transgene between 112 & 120 hr AEL produces no rescue.