The Wnt410xUAS.Ins.cLa cassette in the M{Ins.10xUAS-Wnt4.Ins} construct is flanked on both sides by a 430bp insulator element (from the gypsy natural transposon).
10xUAS sequences regulate expression of the Wnt4 coding sequence. A Syn21 translational enhancer and a single FRT5 site are present in the 5'UTR.