Expression of Mmp2dsRNA.Scer\UAS.cWa under the control of Scer\GAL4btl.PS (by inactivating Scer\GAL80ts.alphaTub84B through heat-shock), severely impairs air sac extension and results in a deformed structure. The characteristic elongated and pointed shape of the air sac is lost. Instead of a single well-defined tip, air sacs display multiple tips and occasionally a multi-lobed structure. Cell proliferation occurs normally.
Randomly generated mutant cells expressing Mmp2dsRNA.Scer\UAS.cWa under the control of Scer\GAL4btl.PS rarely populate the tip-cell territory in the air sac primordium.