Venn diagrams and Volcano plots. A Venn diagram showing the number of genes with significant differences in relative abundance induced by infection point in two sheep flocks when comparing the resistant lines with their respective susceptible counterparts at a false discovery rate (FDR) cutoff < 0.05. B Volcano plots. The red color indicates genes detected as differentially expressed between the resistant groups and susceptible groups at FDR < 0.05. H: HSF flock; T: TSF flock; R: resistant line; S: susceptible line; I: innate infection protocol (primary infection); A: acquired infection protocol (repeated infection).