Fig. 4

Analysis of gene expression by transcriptomics analysis in the 87 individuals. a Unsupervised hierarchical clustering of normalised expression of 5735 contigs differentially expressed in at least one population (using G18 individuals as control). Top dendrogram corresponds to the clustering of individuals based on overall contig expression, highlighted as two main clusters (black and blue). The expression levels of contigs (as Row Z-score) are represented as follows: low expression (blue), moderate expression (white) and high expression (red). b Enrichments of Gene Ontology Biological Process and c KEGG in the 9 different clusters obtained by hierarchical clustering. The numbers in brackets correspond to the total number of contigs in each cluster (bottom, x-axis). d Treeplot based on semantic similarity of GO molecular function obtained after by gene set enrichment analysis (GSEA). The different biological pathways enriched in each gene set (comparative analysis between each site and using G18 as a reference) are indicated at the bottom of the heatmap. The colour-code from blue to red depicts the q-value of the enriched GO terms (grey colour indicates no enrichment)