Fig. 3. Difference in response to heat induction and in the level of expression of hsp22 (A) and hsp70 (B) genes between long- and short-lived lines. The flies were heat induced at 37°C for 2, 5, 10, 20 and 40 min before RNA was extracted for reverse transcription. Quantitative PCR was performed to determine the inducible mRNA expression levels of hsp genes (N=3). Values are means ± S.E.M. ^**P<0.01 versus control; 130-fold increase compared to the control; 80-fold increase compared to the control.