Fig. 3: Heatmap and pathway diagrams of the most highly variable KEGG genes occurring across permafrost sites.

Heatmap shows the scaled relative abundances of KEGG genes that were the most variable across sites, which were clustered using Ward’s minimum variance method. Genes clustered into two primary groups, A and B, which are shown with cool and warm colors, respectively. Subgroups within A are colored dark purple (A1) and green (A2). Subgroups within B are colored orange (B1) and red (B2). Samples (shown in rows) are those occurring in the six primary sample clusters and are organized by cluster for the purpose of visualization. They are labeled by cluster number and a description (including latitude, pH, depth, and archaeal abundance). Clusters 5 and 6 have a similar latitude and pH, and so are labeled by the relative abundance of archaeal genes (archaea-enriched versus non-archaeal) to differentiate between them. Colored boxes overlaid on the heatmap highlight the relationships between groups of genes and clusters of sites. Pathways from each gene group are shown next to the heatmap and are colored dark purple, green, orange, or red to indicate which group they belong to (A1, A2, B1, B2, respectively). Genes from the Ethylmalonyl Co-A pathway were found in Groups B1 and B2, which is indicated by dual coloring of the pathway with red and orange. KO numbers are followed by either a gene name or description in parentheses. The full list of highly variable genes with complete descriptions (shown in the order in which they occur in the heatmap) is available in ScienceBase. In pathway diagrams, dashed arrows indicate multiple steps that are not shown. For the glyoxylate pathway diagram, the abbreviations are as follows: glyoxylate (GLY), malate (MAL), oxaloacetate (OAA), citrate (CIT), isocitrate (ISO), and succinate (SUC).