Journal of Molecular Evolution

, Volume 49, Issue 6, pp 729–735

Monophyly of Lampreys and Hagfishes Supported by Nuclear DNA–Coded Genes

  • Shigehiro  Kuraku
  • Daisuke  Hoshiyama
  • Kazutaka  Katoh
  • Hiroshi  Suga
  • Takashi  Miyata

DOI: 10.1007/PL00006595

Cite this article as:
Kuraku, S., Hoshiyama, D., Katoh, K. et al. J Mol Evol (1999) 49: 729. doi:10.1007/PL00006595

Abstract.

The phylogenetic position of hagfishes in vertebrate evolution is currently controversial. The 18S and 28S rRNA trees support the monophyly of hagfishes and lampreys. In contrast, the mitochondrial DNAs suggest the close association of lampreys and gnathostomes. To clarify this controversial issue, we have conducted cloning and sequencing of the four nuclear DNA–coded single-copy genes encoding the triose phosphate isomerase, calreticulin, and the largest subunit of RNA polymerase II and III. Based on these proteins, together with the Mn superoxide dismutase for which hagfish and lamprey sequences are available in database, phylogenetic trees have been inferred by the maximum likelihood (ML) method of protein phylogeny. It was shown that all the five proteins prefer the monophyletic tree of cyclostomes, and the total log-likelihood of the five proteins significantly supports the cyclostome monophyly at the level of ±1 SE. The ML trees of aldolase family comprising three nonallelic isoforms and the complement component group comprising C3, C4, and C5, both of which diverged during vertebrate evolution by gene duplications, also suggest the cyclostome monophyly.

Key words: Cyclostomes — Gnathostomes — Glycolytic enzymes — Calreticulin — RNA polymerases — Molecular phylogeny

Copyright information

© Springer-Verlag New York Inc. 1999

Authors and Affiliations

  • Shigehiro  Kuraku
    • 1
  • Daisuke  Hoshiyama
    • 1
  • Kazutaka  Katoh
    • 1
  • Hiroshi  Suga
    • 1
  • Takashi  Miyata
    • 1
  1. 1.Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502 JapanJP