title: Unusual number and genomic organization of Hox genes in the tunicate Ciona intestinalis.
abstract: Hox genes are organized in genomic clusters. In all organisms where their role has been studied, Hox genes determine developmental fate along the antero-posterior axis. Hence, these genes represent an ideal system for the understanding of relationships between the number and expression of genes and body organization. We report in this paper that the ascidian Ciona intestinalis genome appears to contain a single Hox gene complex which shows absence of some of the members found in all chordates investigated up to now. Furthermore, the complex appears to be either unusually long or split in different subunits. We speculate that such an arrangement of Hox genes does not correspond to the chordate primordial cluster but occurred independently in the ascidian lineage.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Spagnuolo
authors.forename: Filomena
authors.initials: F
authors.lastname: Ristoratore
authors.forename: Anna
authors.initials: A
authors.lastname: Di Gregorio
authors.forename: Francesco
authors.initials: F
authors.lastname: Aniello
authors.forename: Margherita
authors.initials: M
authors.lastname: Branno
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Lauro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002938:Ciona intestinalis / Q000235:genetics*; D020451:Contig Mapping; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D023061:Gene Order; D018398:Homeodomain Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D018398:Homeodomain Proteins; D004247:DNA