Examines the gene Shaggy (sgg) and glycogen synthase kinase 3 (Sgg/GSK3) in Drosophila. Loss of Sgg gene function to result in accumulation of Cubitus interruptus (Ci); Absence of Sgg and Suppressor of fused to result in wing duplications on Drosophila; Influence of Sgg and GSK3 on hyperphosphorylation of Ci.