Figure 4

Correlations between stress or immune responsive genes and age-responsive genes. a) We analyzed the proportion of genes upregulated (grey bars) or downregulated (black bars) with age for sets of genes identified as stress- or immune-responsive genes in different large scale experiments: E1, microarray analysis of paraquat-induced oxidative stress response [30]; E2, microarray analysis of whole fly bacterial response before 360 h [34]; E3, microarray analysis of whole fly bacterial response and cellular inflammation response [32]; E4, JNK induced genes [12]. Abcissa labels refer to the classification of genes according to the data in each reference. Groups 1, 2, 3, 5 of immune response in E3 refer to genes from Imd/rel group, Toll group, cyto group and others groups in Table 1 of [32]. Note the good correlation between genes induced by stress (oxidative or immune) and genes overexpressed with age, and the poorer correlation between genes repressed by stress and age downregulated genes. In b) the age-responsive genes downregulated after bacterial immune challenge are reported with their fold change induced either by age or by immune stress. Note also the strong repression with age of immune responsive group 3 genes which could correspond to wound response genes. In c) and d) the LPS induced and JNK induced genes are reported with their fold change induced by age. Note in these two gene sets their stronger induction in the thorax compared to that observed in head or in whole fly. In particular note that Jra itself in induced in the thorax of old flies.