UASt regulatory sequences drive expression of an inverted repeat.
Depending on the insertion line used, expression under the control of Scer\GAL4Mef2.PR can result in adult/pharate lethality or early pupal lethality.
Expression under the control of Scer\GAL4pnr-MD237 results in lethality (either before or at the pupal stage), depending on the insertion line used.