Fig. 4. (A–I) Expression of hsp70 genes following heat shock (HS) (A,G) or after 30 min (B,D–F,H) or 1 h (C,I) of recovery (REC) from heat shock in late third-instar larval eye-antennal (A–C,G–I), wing (D) or leg (E) imaginal discs or in brain ganglia (F) as revealed by in situ hybridization with the 87A3'UTR (A–F) or the cDNA (pPW18) (G–I) riboprobe. In situ hybridization patterns with the 87C3'UTR riboprobe were similar to those seen with the 87A3'UTR riboprobe. Note the specific hybridization of the 3'UTR riboprobe with clusters of dividing cells during recovery from heat shock (B–F) in all the imaginal discs and the brain. Insets in D and F show clusters of cells in the wing disc and the optic lobes of brain ganglia, respectively, at higher magnification, demonstrating perinuclear cytoplasmic hybridization with the 3'UTR riboprobe. (J–L) Eye discs of late third-instar larvae immunostained with the 7Fb antibody to show the distribution of Hsp70 in heat-shocked (J) discs and in those allowed to recover from heat shock for 2 h (K) or 4 h (L). Scale bar, 200 µm.