Expression of Hr46^hs.PL under the control of heat shock results in a dramatic loss of hair formation in the wing. The strongest phenotype is induced by heat shock 6-8 hours prior to hair initiation.

About half of Hr46^G60S/Df(2R)12 or Hr46^22-35/Df(2R)12 rescued to the third instar by Hr46^hs.PL and heatshock, display defects in their tracheal system. Although formation and branching appear normal, the cuticular structure of the tracheae is defective. The taenidial folds of the tracheal cuticle can be very distorted. In the more severe cases, this can lead to collapse of the tracheal cuticle and obstruction of the lumen, followed by necrosis. Hr46^G60S/Df(2R)12 or Hr46^22-35/Df(2R)12 rescued by Hr46^hs.PL and heatshock, show three distinct lethal phases during metamorphosis. About 25% die during prepupal development. Some of the dead prepupae are slightly bent at the anterior end and fail to fully evert their anterior spiracles. All dead prepupae display defects in gas bubble translocation. About 70% die in the major lethal phase, during early pupal development. This is associated with incomplete eversion of the adult head and defects in gas bubble translocation, the legs however appear to evert and elongate normally. 5% survive until the pharate adult stage. In contrast to wild-type, salivary glands often survive 24hrs after puparium formation.