Figure 4

Maximum-likelihood phylogenies of H. contortus and C. elegans ligand-gated ion channel families. Figure shows unrooted trees for (a) cation channel and (b) anion channel genes from the two nematode species, with different colors representing each major clade of channels. Within clades, C. elegans genes are colored a lighter shade than H. contortus genes. Both trees show a general pattern of conserved one-to-one orthology, and colored bars indicate where this pattern is broken - by a duplication in H. contortus (with four copies of unc-29), and by loss of some genes - there are four H. contortus genes (acr-26, acr-27, glc-5, glc-6) without orthologs in C. elegans, and seven in C. elegans missing from H. contortus (acr-13/lev-8, acr-18, acr-23, glc-1, lev-8, lgc-48, lgc-54). All of these genes are shown in large bold type. A truncated ortholog of C. elegans acr-9 is present in H. contortus but is omitted from this phylogeny. Values near internal nodes are Shimodaira-Hasegawa test support values - with support values of 1.0 on all other nodes omitted for clarity.