A cDNA encoding the A variant of the sgg product is driven by a heat inducible promoter.
Flies expressing sggA.hs have a wild-type tissue polarity phenotype in the wing.
Different classes of heart phenotype are produced when embryos carrying sggA.hs are heat shocked for 40 minutes during 3.5 to 4.5 hours of development; 15% of embryos show an increase in heart formation, and 14% of embryos show a decrease in heart formation.
Heat shock for 30 minutes at 3.5 hours of development has no effect on heart precursor formation.
Expression of the sgg-A protein is sufficient to rescue all aspects of the sgg mutant phenotype.
Overexpression of sgg can suppress the P{sev-wg.C} phenotype, almost complete loss of interommatidial bristles.