Figure 4. Lifespan extension by KRG is mediated through the Sir2 pathway. (A) The mRNA level of dSir2 was analyzed in the whole body of male fruit flies fed a KRG-containing diet or a control diet for 7 or 40 days. (B) Survival of dSir2 null mutant flies (dSir22A-7-11, dashed lines) and control flies (w1118, solid lines) fed a KRG-containing diet (lines with open dots) or a control diet (lines with closed dots).