Fig. 2. Effects of heat-shock temperature and time after heat shock on normalized relative Hsp70 concentration in lysates of whole 4-day-old flies of the Oregon R (OR25), T25 and T32 strains of Drosophila melanogaster. Inset (top right): effects of heat-shock temperature on Hsp70 levels 1h after a 30min heat shock. Results are expressed relative to the signal obtained with a standard derived from heat-shocked D. melanogaster tissue culture cells (see Materials and methods). Each point is the mean of 5–9 independendent measurements (except for OR25 at 34°C, for which N=3). Means are plotted ±1 S.E.M., which the plotted points often obscure. The arrow in the inset indicates a mean for T32 strain flies reared at 25°C. All axes use identical scales to facilitate comparison.