Sequence evolution of Hox genes across Lepidoptera. (A) Phylogenetic tree of Hox and Hox-derived homeodomains across 46 Lepidoptera species. Shx gene clades are colored orange, red, green, and blue; canonical Hox genes are colored yellow. The names of the Hox genes are placed alongside their clade in the tree. (B) Shx genes show elevated sequence evolution following loss of ShxD in Lycaenidae. Results of pairwise identity of Shx genes between Lycaenidae species and non-Lycaenidae species. For each gene (ShxA–C), pairwise identity between Lycaenidae and all other Lepidoptera species with normal Shx gene count (darker shade boxplot) is compared with pairwise identity between all Lepidoptera species with normal Shx gene count (lighter shade boxplot). Each pair of boxplots (light shade and dark shade) are colored according to the color code for each of the Shx genes. Wilcoxon rank-sum test was performed between pairwise identity for Lycaenidae and non-Lycaenidae species: (*) P-value < 0.05.
