Overexpression of Mmus\Ect2Δ.Scer\UAS by Scer\GAL4prd.RG1 leads to 100% embryonic lethality. Most cells within the embryonic segments expressing Mmus\Ect2Δ.Scer\UAS become multinucleate, caused by a failure of cleavage furrow initiation. Likewise the contractile ring is not assembled.