Fig 7. hsp22 expression is not induced in boss mutant flies.

(A) Expression of hsp22 mRNA was measured in 7-, 21-and 35-days-old control and boss mutant flies by using qRT-PCR (n = 3, 10 flies per replicate). Data are means ± SEM (t-test, *P<0.05). (B) DsRed fluorescence was observed in control and boss mutant flies bearing the Hsp22-DsRed reporter. DsRed fluorescence progressively increased during aging in control but not in boss mutant flies. (C) Flies bearing the Hsp22-DsRed reporter were transferred to a diet containing 0.5% H₂O₂ for 24 h, and then DsRed fluorescence was observed. Under this oxidative stressful condition, boss mutant flies still failed to exhibit increased hsp22 expression, suggesting dysfunctional mitochondria and oxidative stress dysregulation.