Fig. 9. Analysis of heat-shock element (HSE) binding activity in OR25 and T32 flies reared at 25°C. The latter strain yielded the same results as for T25 and T32 flies reared at 32°C; data not shown. (A) Effect of heat shock and identification of specific HSE complexes (A–C) in the OR25 strain. Lane 1, control (25°C); lane 2, after a 30min 37.5°C heat shock; lane 3, a 30min 37.5°C heat shock plus anti-heat-shock-factor (HSF) antibody, with supershift implicating HSF as a component of complex 1; lane 4, a 30min 37.5°C heat shock plus anti-Ku autoantigen antibody, with supershift implicating Ku autoantigen as a component of complex 2; lane 5, a 30min 37.5°C heat shock plus 200-fold molar excess of unlabeled HSE. This image is a composite of several gels. (B) Effect of heat-shock intensity and recovery time on HSE complexes in the two strains.