Fig. 6. Rig protein is expressed in the brains and salivary glands of second and early third instar larvae. Organs were dissected from rig mutant (l(2)k07839/Df(2R)exu¹) (A-C) or control (l(2)k07839/CyO or Df(2R)exu¹/CyO) (D-I) larvae staged at either 0-4 hours (A,D,G) or 16-24 hours (B,E,H) after the first-to-second instar larval molt, or 0-4 hours after the second-to-third instar larval molt (C,F,I). Brains (A-F) or salivary glands (G-I) were fixed and stained to detect Rig protein. The specificity of the antibodies was demonstrated by the absence of staining in rig mutant larvae (compare A-C with D-F). Background staining can occasionally be seen in the ring gland (B).