Ectopic expression during embryonic cellularisation radically changes embryonic membrane surface aspects and modifies cell shape which is associated with a polarity-dependent deregulation of the actin cytoskeletal network. Heat shock of single insertion strains during larval stages and pupariation produces a phenotype only in the wing, a weak ectopic crossvein. Heat shock of a polyinsertional strain for 6-8 hours induces a number of different and reproducible cuticular phenotypes mainly affecting the wing blade but also the thorax and abdomen. Developmental critical periods can be defined, heat shock 12-18 hours after the start of pupation causes wing notches, heat shock at 18-24 hours causes holes in the wing, missing vein parts and elongated wings, heat shock at 24-30 hours causes ectopic crossveins, heat shock at 24-42 hours causes forked bristles on the thorax and heat shock at 30-42 hours causes interrupted abdominal segments. Heat shock at 1-18 hours causes 100% lethality, at 30-42 hours 65% lethality.

In early embryos overexpression induces a strong lethality. Later in development, at the beginning of pupariation, overexpression leads to several distinct imaginal phenotypes that mostly affect the wing blade.