Fig. 2
From: Specialized metabolic functions of keystone taxa sustain soil microbiome stability
Functional gene co-occurrence networks at every dilution level. Valid co-occurrence of functional genes with strong (Spearman’s correlation coefficient r > 0.75) and significant (P value < 0.01) correlations at 10-1 (a), 10-4 (b), 10-7 (c), and 10-10 (d) dilution levels. Color points (nodes) are gene categories (KEGG functional gene annotated level 3). The size of each point is the node degree (proportional to the number of connections). A blue connection (edge) between two nodes indicates a negative correlation, while a red edge indicates a positive correlation. The capitals inside the nodes are module hubs in the individual network. Dotted line frames encompass the gene aggregates. The left frame shows the gene aggregate of “metabolic processes,” and the right frame shows the gene aggregate of “environmental signal responses” for each network (only one gene aggregate was observed in the 10-10 diluted network). The nodes labeled by letters (A to H) are keystone genes, and the details for these keystone genes are listed in Table S2