Insertion of a P{GS} element at -35bp (relative to the transcription start site).
Flies expressing P{GS}sopGS2141 under the control of Scer\GAL429BD show semi-lethality and have blistered wings. Flies expressing P{GS}sopGS2141 under the control of Scer\GAL4dpp.blk1 lack the anterior crossvein.