Complete Sequence and Analysis of the Plastid Genome of the Unicellular Red Alga Cyanidioschyzon Merolae

DNA Res. 2003 Apr 30;10(2):67-77. doi: 10.1093/dnares/10.2.67.


The complete nucleotide sequence of the plastid genome of the unicellular primitive red alga Cyanidioschyzon merolae 10D (Cyanidiophyceae) was determined. The genome is a circular DNA composed of 149,987 bp with no inverted repeats. The G + C content of this plastid genome is 37.6%. The C. merolae plastid genome contains 243 genes, which are distributed on both strands and consist of 36 RNA genes (3 rRNAs, 31 tRNAs, tmRNA, and a ribonuclease P RNA component) and 207 protein genes, including unidentified open reading frames. The striking feature of this genome is the high degree of gene compaction; it has very short intergenic distances (approximately 40% of the protein genes were overlapped) and no genes have introns. This genome encodes several genes that are rarely found in other plastid genomes. A gene encoding a subunit of sulfate transporter (cysW) is the first to be identified in a plastid genome. The cysT and cysW genes are located in the C. merolae plastid genome in series, and they probably function together with other nuclear-encoded components of the sulfate transport system. Our phylogenetic results suggest that the Cyanidiophyceae, including C. merolae, are a basal clade within the red lineage plastids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Gene Library
  • Genome, Plant*
  • Models, Genetic
  • Molecular Sequence Data
  • Open Reading Frames
  • Phylogeny
  • Plastids / genetics*
  • RNA, Ribosomal / genetics
  • RNA, Transfer / genetics
  • Rhodophyta / genetics*
  • Sequence Analysis, DNA


  • RNA, Ribosomal
  • RNA, Transfer

Associated data

  • GENBANK/AB002583