Research Paper Volume 5, Issue 9 pp 682—691

Figure 1. Effects of increased dSir2 expression on life span vary under different conditions. (A) When two different UAS-dSir2 expressing lines are driven by the Tubulin-Gal4 driver, one line extends life span (Sir2-3), while the other is detrimental (Sir2-1), compared to the control (Tubulin-Gal4>w¹¹¹⁸). (A, inset) Sir2-1 displays very highly increased dSir2 expression, while Sir2-3 increases dSir2 expression more moderately. (B) When the Sir2-1 transgene is induced to express dSir2 by the Tubulin-Gene Switch driver, life span is decreased. (B, inset) dSir2 is expressed at greater than 50-fold Tubulin-Gene Switch>Sir2-1 flies. (C) In the Tubulin-Gene Switch>Sir2-3 flies, dSir2 is mildly elevated and life span extended when comparing the ethanol-only condition (no RU-486) to the genetic background control. (C, inset) The induction of higher levels of dSir2 from Sir2-3 using RU-486 does not further increase life span. (D) When the Sir2-3 transgene is expressed using the neuron-specific ELAV Gene Switch driver, life span is extended when RU-486 is used. (D, inset) dSir2 expression is 5-fold increased in ELAV-Gene Switch>Sir2-3 flies. (E, inset) Some UAS-dSir2 lines show elevated dSir2 levels in a heterozygous state without the presence of a driver. (E) Fly lines that show an increase in dSir2 levels also extend life span in the absence of a driver. Error bars represent SD of 3 biological replicates. Life span statistics can be found in table S1, and qPCR p-values in table S2.