Current Genetics

, Volume 30, Issue 1, pp 29–33

UAG is a sense codon in several chlorophycean mitochondria

Authors

  • Yasuko Hayashi-Ishimaru
    • Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569, Japan
  • T. Ohama
    • Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569, Japan
  • Yoshimi Kawatsu
    • Division of Natural Science, Osaka Kyoiku University, Kasiwara, Osaka 582, Japan
  • Keiko Nakamura
    • Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569, Japan
  • Syozo Osawa
    • Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki, Osaka 569, Japan
ORIGINAL PAPER

DOI: 10.1007/s002940050096

Cite this article as:
Hayashi-Ishimaru, Y., Ohama, T., Kawatsu, Y. et al. Curr Genet (1996) 30: 29. doi:10.1007/s002940050096

Abstract

 The mitochondrial genetic code of those land plants and green algae that have been examined does not deviate from the universal one. A red alga, Chondrus crispus, is the sole reported example throughout the algae that uses a deviant (non-universal) mitochondrial genetic code (UGA=Trp). We have analyzed 366-bp DNA sequences of the gene for mitochondrial cytochrome oxidase subunit I (COXI) from ten chlorophyceaen algae, and detected 3–8 in-frame UAG codons in the sequences of five species. Comparisons of these sequences with those of other algae and land plants have shown that most of the UAG sites in Hydrodictyon reticulatum, Pediastrum boryanum and Tetraedron bitridens correspond to alanine, and those of Coelastrum microporum and Scenedesmus quadricauda to leucine. The three species in which UAG probably codes for alanine are characterized by zoospore formation in asexual reproduction and form a clade in the COXI phylogenetic tree. The two species in which UAG codes for leucine are known to form daughter coenobia and pair in the tree. This is the first report on a deviant mitochondrial genetic code in green algae. Mutational change(s) in the release factor corresponding to UAG would be involved in these code changes. No genetic code deviation has been found in five other species examined.

Key words Deviant genetic codeCOXIChlorophyceaen mitochondriaRelease factor

Copyright information

© Springer-Verlag Berlin Heidelberg 1996