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Regulatory Genes in Ancestral Chordates

  1. Yasunori Sasakura

Published Online: 15 SEP 2009

DOI: 10.1002/9780470015902.a0021774



How to Cite

Sasakura, Y. 2009. Regulatory Genes in Ancestral Chordates. eLS. .

Author Information

  1. University of Tsukuba, Shimoda, Shizuoka, Japan

Publication History

  1. Published Online: 15 SEP 2009


The phylum ‘Chordate’ includes amphioxus, tunicate and vertebrate. The three groups evolved from a common ancestor. The evolution of chordates is a fascinating subject for biologists, who have long pondered which changes in the genome and genes were critical to the evolution, with no real resolution to this issue. Recent genome projects in the chordates have revealed a repertoire of so-called regulatory genes, and comparison of these essential genes for development has provided insights into chordate evolution. The ancestral chordate is estimated to have had approximately 80% of the genes in the extant chordate genomes. Some regulatory genes are specific to specific lineages, which may have led to the separation of amphioxus, tunicates and vertebrates.

Key concepts

  • Small subsets of genes encoding transcription factors and signal transductions play roles as conductors during development. These genes are called regulatory genes. Genetic changes in regulatory genes served as major driving forces for the evolution of chordates. The regulatory genes present in the ancestral chordate can be deduced by comparing the extant chordate genomes. This information is crucial to understand the evolution of chordates.


  • amphioxus;
  • tunicate;
  • vertebrate;
  • Ciona intestinalis;
  • evolution