RRC ID 20167
Author Turmel M, Lemieux C, Burger G, Lang BF, Otis C, Plante I, Gray MW.
Title The complete mitochondrial DNA sequences of Nephroselmis olivacea and Pedinomonas minor. Two radically different evolutionary patterns within green algae.
Journal Plant Cell
Abstract Green plants appear to comprise two sister lineages, Chlorophyta (classes Chlorophyceae, Ulvophyceae, Trebouxiophyceae, and Prasinophyceae) and Streptophyta (Charophyceae and Embryophyta, or land plants). To gain insight into the nature of the ancestral green plant mitochondrial genome, we have sequenced the mitochondrial DNAs (mtDNAs) of Nephroselmis olivacea and Pedinomonas minor. These two green algae are presumptive members of the Prasinophyceae. This class is thought to include descendants of the earliest diverging green algae. We find that Nephroselmis and Pedinomonas mtDNAs differ markedly in size, gene content, and gene organization. Of the green algal mtDNAs sequenced so far, that of Nephroselmis (45,223 bp) is the most ancestral (minimally diverged) and occupies the phylogenetically most basal position within the Chlorophyta. Its repertoire of 69 genes closely resembles that in the mtDNA of Prototheca wickerhamii, a later diverging trebouxiophycean green alga. Three of the Nephroselmis genes (nad10, rpl14, and rnpB) have not been identified in previously sequenced mtDNAs of green algae and land plants. In contrast, the 25,137-bp Pedinomonas mtDNA contains only 22 genes and retains few recognizably ancestral features. In several respects, including gene content and rate of sequence divergence, Pedinomonas mtDNA resembles the reduced mtDNAs of chlamydomonad algae, with which it is robustly affiliated in phylogenetic analyses. Our results confirm the existence of two radically different patterns of mitochondrial genome evolution within the green algae.
Volume 11(9)
Pages 1717-30
Published 1999-9-1
DOI 10.1105/tpc.11.9.1717
PMID 10488238
PMC PMC144307
MeSH Animals Base Sequence Chlamydomonas / genetics Chlorophyta / classification Chlorophyta / genetics* Chromosome Mapping DNA, Mitochondrial / genetics* Endoribonucleases / genetics Evolution, Molecular* Genome Molecular Sequence Data Nucleic Acid Conformation Phylogeny RNA / chemistry RNA / genetics RNA, Catalytic / genetics Ribonuclease P Species Specificity
IF 9.618
Times Cited 126
Algae NIES-484