Hox genes and the diversification of insect and crustacean body plans

The expression of four Hox genes in the branchiopod crustacean Artemia franciscana have been compared with Hox gene patterns from insects to investigate the macroevolutionary changes in body architecture. Though crustaceans and insects share a common origin of segmentation, the specialized trunk segments may have independent origins. The three trunk genes in Artemia, Antp, Ubx, and abdA, have largely overlapping domains in the uniform thoracic region. In insects these genes form distinct segment types in thorax and abdomen.