Heat-shock DE genes in transcriptional WGP differ between larvae and adults
Our GO analyses provide a broad characterization of the functions associated with transcriptional plasticity. However, these analyses might also defuse the role of the most important functions in the heat-shock response, which involves a massive up-regulation of genes associated with molecular chaperones (HSPs) and proteolysis genes (Sørensen et al., 2005; Mahat et al., 2016). Thus, we next investigated the number and direction of gene expression in these gene categories (Figure 3b). We found that the number of Hsp genes and their relative level of up-regulation are substantially higher in adults (11 up-regulated genes) than in larva samples (5 upregulated genes and 2 down-regulated genes) (X2 , p = 0.002, Figure 3b). On the other hand, while the number of up-regulated proteolysis genes is substantially higher in larvae (56 genes) than in adults (17 genes), the relative level of up-regulation seems to be higher in adults (X2 , p < 0.001, Figure 3b). These results demonstrate functional differences in the heat-shock response between life stages, suggesting that larvae rely primarily on proteolysis genes. In contrast, adults rely more on Hsp genes during acclimation in WGP to prepare for upcoming thermal stress.