Unusual number and genomic organization of Hox genes in the tunicate Ciona intestinalis

• Published in: Gene 2003-05, Vol.309 (2), p.71-79
• Main Authors: Spagnuolo, Antonietta, Ristoratore, Filomena, Di Gregorio, Anna, Aniello, Francesco, Branno, Margherita, Di Lauro, Roberto
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Ascidian; Chromosome walking; Ciona intestinalis - genetics; Cluster Hox; Contig Mapping; DNA - chemistry; DNA - genetics; DNA, Complementary - chemistry; DNA, Complementary - genetics; Gene Order; Homeodomain Proteins - genetics; Molecular Sequence Data; Multigene Family - genetics; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Spatial and temporal colinearity
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/S0378-1119(03)00488-8

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.