Summary of treatments for the gene expression study (Experiment 3).

In this study, we used a subset of four populations representative of the extremes of MG endemism and tolerance (two “Less-tolerant”, two “More-tolerant”). Harderian glands were collected from all individuals three days post-inoculation with M. gallisepticum. *The sample from one bird from HI showed a near zero read-count after sequencing and was excluded from subsequent analyses.