Expression of wg^hs.PH in a wild-type background using a single heat shock at 4 hours or 6 hours of development results in the replacement of denticle belts by naked cuticle, particularly along the ventral midline. Expression of wg^hs.PH by three consecutive heat shocks in wg^l-17 embryos restores denticle diversity and naked cuticle. Expression of wg^hs.PH using a single heat shock at 6 hours of development in wg^l-17 embryos produces specification of naked cuticle along the ventral midline, but little denticle diversity. The denticles are reoriented toward the ventral midline.