title: Hox genes and the phylogeny of the arthropods.
abstract: The arthropods are the most speciose, and among the most morphologically diverse, of the animal phyla. Their evolution has been the subject of intense research for well over a century, yet the relationships among the four extant arthropod subphyla - chelicerates, crustaceans, hexapods, and myriapods - are still not fully resolved. Morphological taxonomies have often placed hexapods and myriapods together (the Atelocerata) [1, 2], but recent molecular studies have generally supported a hexapod/crustacean clade [2-9]. A cluster of regulatory genes, the Hox genes, control segment identity in arthropods, and comparisons of the sequences and functions of Hox genes can reveal evolutionary relationships [10]. We used Hox gene sequences from a range of arthropod taxa, including new data from a basal hexapod and a myriapod, to estimate a phylogeny of the arthropods. Our data support the hypothesis that insects and crustaceans form a single clade within the arthropods to the exclusion of myriapods. They also suggest that myriapods are more closely allied to the chelicerates than to this insect/crustacean clade.
authors.affiliation: University Museum of Zoology, Downing Street, CB2 3EJ, Cambridge, United Kingdom. ccook@phillips.exeter.edu
authors.forename: C E
authors.initials: CE
authors.lastname: Cook
authors.forename: M L
authors.initials: ML
authors.lastname: Smith
authors.forename: M J
authors.initials: MJ
authors.lastname: Telford
authors.forename: A
authors.initials: A
authors.lastname: Bastianello
authors.forename: M
authors.initials: M
authors.lastname: Akam
mesh_terms: D000818:Animals; D001181:Arthropods / Q000145:classification / Q000235:genetics*; D005801:Genes, Homeobox; D010802:Phylogeny