title: Phylogenetic analysis of T-Box genes demonstrates the importance of amphioxus for understanding evolution of the vertebrate genome.
abstract: The duplication of preexisting genes has played a major role in evolution. To understand the evolution of genetic complexity it is important to reconstruct the phylogenetic history of the genome. A widely held view suggests that the vertebrate genome evolved via two successive rounds of whole-genome duplication. To test this model we have isolated seven new T-box genes from the primitive chordate amphioxus. We find that each amphioxus gene generally corresponds to two or three vertebrate counterparts. A phylogenetic analysis of these genes supports the idea that a single whole-genome duplication took place early in vertebrate evolution, but cannot exclude the possibility that a second duplication later took place. The origin of additional paralogs evident in this and other gene families could be the result of subsequent, smaller-scale chromosomal duplications. Our findings highlight the importance of amphioxus as a key organism for understanding evolution of the vertebrate genome.
authors.affiliation: Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: I
authors.initials: I
authors.lastname: Ruvinsky
authors.forename: L M
authors.initials: LM
authors.lastname: Silver
authors.forename: J J
authors.initials: JJ
authors.lastname: Gibson-Brown
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002816:Chordata, Nonvertebrate / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D020440:Gene Duplication; D016678:Genome; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D020825:T-Box Domain Proteins / Q000737:chemistry / Q000235:genetics*; D014714:Vertebrates / Q000145:classification / Q000235:genetics*
chemical_list: D020033:Protein Isoforms; D020825:T-Box Domain Proteins