title: Expression of homeobox genes shows chelicerate arthropods retain their deutocerebral segment.
abstract: Expression patterns of six homeobox containing genes in a model chelicerate, the oribatid mite Archegozetes longisetosus, were examined to establish homology of chelicerate and insect head segments and to investigate claims that the chelicerate deutocerebral segment has been reduced or lost. engrailed (en) expression, which has been used to demonstrate the presence of segments in insects, fails to demonstrate a reduced deutocerebral segment. Expression patterns of the chelicerate homologs of the Drosophila genes Antennapedia (Antp), Sex combs reduced (Scr), Deformed (Dfd), proboscipedia (pb), and orthodenticle (otd) confirm direct correspondence of head segments. The chelicerate deutocerebral segment has not been reduced or lost. We make further inferences concerning the evolution of heads and Hox genes in arthropods.
authors.affiliation: Department of Zoology, The Natural History Museum, Cromwell Road, London, SW7 5BD, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Telford
authors.forename: R H
authors.initials: RH
authors.lastname: Thomas
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D019143:Evolution, Molecular; D015870:Gene Expression; D005801:Genes, Homeobox; D008925:Mites / Q000196:embryology / Q000235:genetics*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers