938 amino acids of the extracellular domain have been removed, though the transmembrane region has been retained.
When hbsΔECD.Scer\UAS is driven by Scer\GAL4twi.PB and Scer\GAL4Mef2.PR simultaneously in the embryo, muscle phenotypes are seen. A block in myoblast fusion and muscle loss is seen. Serious defects in the visceral mesoderm are also seen, and a serious reduction in visceral muscle progenitors.