RRC ID 19781
Author Hayashi-Ishimaru Y, Ehara M, Inagaki Y, Ohama T.
Title A deviant mitochondrial genetic code in prymnesiophytes (yellow-algae): UGA codon for tryptophan.
Journal Curr. Genet.
Abstract The sequence of a representative mitochondrial gene COXI, encoding cytochrome c oxidase subunit I, was determined in five species that cover all the orders of the Prymnesiophyta with the exception of the Pavlovales. Through this analysis, we noticed that the 'stop' codon UGA appears frequently and, specifically, at conserved tryptophan (Trp) sites of the gene. We showed these sites were not edited in the corresponding mRNA in one of these species, Isochrysis galbana. Therefore, it is most likely that the UGA codon is used for Trp, and not as a stop codon, in prymnesiophytes. All the analyzed prymnesiophytes made a tight cluster on the COXI phylogenetic tree which includes representative species of green-algae, land plants, yellow-green algae, eustigmatophytes and a red-alga. This suggests a monophyletic origin for the prymnesiophytes. The same deviant genetic code, i.e. UGA for Trp, has also been found in the red-alga, Chondrus crispus. In spite of the fact that this red-alga and the prymnesiophytes, share the same deviant genetic code for Trp, close affinity between the two groups was not statistically supported by the phylogenetic analysis of COXI sequences.
Volume 32(4)
Pages 296-9
Published 1997-10
PMID 9342410
MeSH Base Sequence Codon / genetics* Conserved Sequence DNA, Mitochondrial / genetics* Electron Transport Complex IV / genetics* Eukaryota / enzymology Eukaryota / genetics* Genetic Code* Phylogeny Plants / genetics RNA, Messenger / biosynthesis RNA, Messenger / genetics Tryptophan*
IF 3.574
Times Cited 21
Algae NIES-353 NIES-388 NIES-8