Research Paper Volume 8, Issue 8 pp 1759—1780

Figure 6. Gene expression analysis reveals ets-7 as an important effector of SA. (A) Heat map of genes differentially regulated by treatment in 15 day CE. 109 probe sets had at least a 25% change in expression concordant in both samples. These include 26 genes upregulated by both doses of SA (group I), 38 genes more strongly downregulated by 500 µM SA than 100 µM SA (Group II), 15 genes with variable downregulation (Group III), and 30 genes downregulated regardless of dose of SA (Group IV). (B) Real-time RT-PCR validation of microarray results on selected genes. The genes, siah-1 and sma-4 showed downregulation by SA in day 15 WT N2 worms, and F13D12.6 and ets-7 showed upregulation by SA. Data are expressed as means ± SEM from five independent experiments. *P < 0.05 as compared to vehicle control, **P < 0.01 as compared to vehicle control. (C) Kaplan-Meier survival curves for concentration dependency of SA-mediated ets-7 knock-out mutant lifespan extension. (D) Summary of SA-treated ets-7 knock-out mutant median lifespan. SA administration does not affect median lifespan of ets-7 knock-out mutants. Data are expressed as means ± SEM from five independent experiments. P = 0.40. (E) Real-time RT-PCR quantification of ets-7 in non-functional SIR-2.1 mutant nematodes treated with increasing doses of SA. Transcriptional levels for ets-7 were increased by 25% in day 15 N2 WT worms by SA administration, and a dose-dependent increase in ets-7 mRNA levels can be observed in day 15 SIR-2.1 mutants. Data are expressed as means ± SEM from four independent experiments. *P < 0.05 as compared to vehicle control, and **P < 0.01 as compared to vehicle control.