Inter-species genetic regulation of longevity: Δhns E. coli activate C. elegans DAF-16 in distinct ways from IIS

We confirmed that the life span of C. elegans feeding hns mutant E. coli was increased. hns mutant E. coli was found to regulate lifespan of C. elegans through daf-16 activation in C. elegans. It is well known that daf-16 is the transcription factor of the insulin/IGF-1 signaling pathway and it is known to regulate downstream genes such as longevity, stress response, and dauer diapause regulation genes. Thus, we performed Next Generation Sequencing(NGS) to investigate the downstream genes regulated by daf-16 in C. elegans that are activated by hns mutant E. coli. N2 wild type worms and daf-16 mutant worms were fed with BW25113 wild type E. coli and hns mutant E. coli, respectively, and then NGS was performed by harvesting the worms and purifying the RNA. We investigated how the downstream genes of daf-16 of C. elegans, which is regulated by hns mutant E. coli, differs from the downstream genes of daf-16 of C. elegans, which is regulated by the insulin/IGF-1 signaling pathway. To do this, we carried out the analysis including two previous studied papers that analyzed the daf-16 downstream genes related to the insulin/IGF-1 signaling pathway. Surprisingly, only 6 genes were up-regulated in all three experiments and 288 genes were found to be dependent on daf-16 and hns mutant E. coli. This study indicated that hns mutant E. coli regulate daf-16 distinct from insulin/IGF-1 signaling pathway on C. elegans.