title: Unusual gene order and organization of the sea urchin hox cluster.
abstract: While the highly consistent gene order and axial colinear patterns of expression seem to be a feature of vertebrate hox gene clusters, this pattern may be less well conserved across the rest of the bilaterians. We report the first deuterostome instance of an intact hox cluster with a unique gene order where the paralog groups are not expressed in a sequential manner. The finished sequence from BAC clones from the genome of the sea urchin, Strongylocentrotus purpuratus, reveals a gene order wherein the anterior genes (Hox1, Hox2 and Hox3) lie nearest the posterior genes in the cluster such that the most 3' gene is Hox5. (The gene order is 5'-Hox1, 2, 3, 11/13c, 11/13b, 11/13a, 9/10, 8, 7, 6, 5-3'.) The finished sequence result is corroborated by restriction mapping evidence and BAC-end scaffold analyses. Comparisons with a putative ancestral deuterostome Hox gene cluster suggest that the rearrangements leading to the sea urchin gene order were many and complex.
authors.affiliation: Division of Biology and the Beckman Institute, California Institute of Technology, Pasadena, CA 91125, USA. acameron@caltech.edu
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Cameron
authors.forename: Lee
authors.initials: L
authors.lastname: Rowen
authors.forename: Ryan
authors.initials: R
authors.lastname: Nesbitt
authors.forename: Scott
authors.initials: S
authors.lastname: Bloom
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Rast
authors.forename: Kevin
authors.initials: K
authors.lastname: Berney
authors.forename: Cesar
authors.initials: C
authors.lastname: Arenas-Mena
authors.forename: Pedro
authors.initials: P
authors.lastname: Martinez
authors.forename: Susan
authors.initials: S
authors.lastname: Lucas
authors.forename: Paul M
authors.initials: PM
authors.lastname: Richardson
authors.forename: Eric H
authors.initials: EH
authors.lastname: Davidson
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Peterson
authors.forename: Leroy
authors.initials: L
authors.lastname: Hood
mesh_terms: D000818:Animals; D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial; D015870:Gene Expression; D023061:Gene Order; D005801:Genes, Homeobox / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D047270:Strongylocentrotus purpuratus / Q000235:genetics*
chemical_list: D035683:MicroRNAs