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ZFIN ID: ZDB-PUB-110928-3
Gene duplications in the prototypical cephalochordate amphioxus
Minguillón, C., Ferrier, D.E., Cebrián, C., and Garcia-Fernàndez, J.
Date: 2002
Source: Gene   287(1-2): 121-128 (Journal)
Registered Authors: Minguillón, Carolina
Keywords: Hox, Evx, Emx, Branchiostoma, genome duplication, evolutionary developmental biology, evo-devo
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chordata, Nonvertebrate/embryology
  • Chordata, Nonvertebrate/genetics*
  • DNA, Complementary/chemistry
  • DNA, Complementary/genetics
  • Embryo, Nonmammalian/metabolism
  • Embryonic Development
  • Evolution, Molecular
  • Gene Duplication*
  • Gene Expression Regulation, Developmental
  • Genes, Homeobox/genetics*
  • Homeodomain Proteins/genetics*
  • In Situ Hybridization
  • Larva/growth & development
  • Larva/metabolism
  • Molecular Sequence Data
  • Phylogeny
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
PubMed: 11992730 Full text @ Gene

The new discipline of Evolutionary Developmental Biology (Evo-Devo) is facing the fascinating paradox of explaining morphological evolution using conserved pieces or genes to build divergent animals. The cephalochordate amphioxus is the closest living relative to the vertebrates, with a simple, chordate body plan, and a genome directly descended from the ancestor prior to the genome-wide duplications that occurred close to the origin of vertebrates. Amphioxus morphology may have remained relatively invariant since the divergence from the vertebrate lineage, but the amphioxus genome has not escaped evolution. We report the isolation of a second Emx gene (AmphiEmxB) arising from an independent duplication in the amphioxus genome. We also argue that a tandem duplication probably occurred in the Posterior part of the Hox cluster in amphioxus, giving rise to AmphiHox14, and discuss the structure of the chordate and vertebrate ancestral clusters. Also, a tandem duplication of Evx in the amphioxus lineage produced a prototypical Evx gene (AmphiEvxA) and a divergent gene (AmphiEvxB), no longer involved in typical Evx functions. These examples of specific gene duplications in amphioxus, and other previously reported duplications summarized here, emphasize the fact that amphioxus is not the ancestor of the vertebrates but ‘only’ the closest living relative to the ancestor, with a mix of prototypical and amphioxus-specific features in its genome.