Two classes of genes stand out as significantly differentially-expressed among locations. These are ribosomal proteins of both the small and large subunits as well as the cytoplasmic and mitochondrial compartments, and proteins involved in oxidative phosphorylation, which are highly up-regulated in half of the Agadir residents (Supplementary Fig. 4a online). All of the transcripts encoding these proteins form a module of co-regulated genes, but as shown in Supplementary Figure 4b online, it is noteworthy that this module is not co-expressed with the SNORDs, which tend to be relatively down-regulated in Agadir but are particularly high in the Arab women from Ighrem. Regulation of ribosomal biosynthesis may be related to response to viral infection, and it also seems to be involved in tumorigenesis in conjunction with mitochondrial activity20,21. Oxidative phosphorylation is correlated with renal health and the production or disposal of free radicals22, so our data suggests that deeper evaluation of health risks associated with lifestyle transitions may be revealing.
