Phylogeny and expression of glutathione synthetase genes in G. pallida . (A) Phylogeny of all G. pallida glutathione synthetase genes that can be aligned over at least 200 bp. Non-G. pallida sequences are from Meloidogyne incognita, Bursaphelenchus xylophilus, Wuchereria bancrofti and from mammals. Red sequences are predicted to have signal peptides. (B) Different clades of these genes show different expression dynamics. The single-copy outgroup sequence, apparently shared by all nematodes, is constitutively expressed across the lifecycle (black line). Members of the clade shared with some M. incognita sequences (green) show a peak of expression at 14 dpi, while the G. pallida-specific expansion (purple in panel A) shows a peak of expression at 7 dpi, a pattern more pronounced in copies predicted to have signal peptides (red) than those without (blue). Lines are mean expression across gene copies for each lifecycle stage; shading covers a 99% exponential confidence interval for the mean.