Fig. 2. rig mutant larvae have defective mouthhooks. (A) The mouthhooks of control (+/Df(2R)exu¹) second instar larvae have three to four large teeth, while control third instar larvae (B) have larger mouthhooks with numerous smaller teeth. (C) rig mutants (l(2)k07839/Df(2R)exu¹) that die as prolonged second instar larvae have normal second instar mouthhooks. (D) The mouthhooks of rig mutant that die as third instar larvae are severely malformed. (E) rig mutants that die while trying to molt have two sets of mouthhooks, a normal second instar set (red arrows) and a malformed third instar set (black arrows).