Hox gene cluster evolution across Insecta. (A) Comparison of the general structure of the Hox gene cluster between representative species for Hymenoptera (Bombus terrestris), Coleoptera (Tribolium castaneum), Diptera (Drosophila melanogaster), and Lepidoptera. Lepidoptera are shaded in an orange box and split between non-Ditrysia species (Neomicropteryx cornuta) and Ditrysia (represented by 122 species in our data set). Lepidoptera-specific Shx genes are colored orange (ShxA), red (ShxB), green (ShxC), and blue (ShxD) in this figure and throughout the paper. (B) Genomic location of Hox genes in A. gamma with corresponding exon structures and genomic distances annotated below. Silhouette images of B. terrestris, T. castaneum, and D. melanogaster were taken from PhyloPic (phylopic.org).
