title: The Plastid Genome of the Cryptomonad Teleaulax amphioxeia.
abstract: Teleaulax amphioxeia is a photosynthetic unicellular cryptophyte alga that is distributed throughout marine habitats worldwide. This alga is an important plastid donor to the dinoflagellate Dinophysis caudata through the ciliate Mesodinium rubrum in the marine food web. To better understand the genomic characteristics of T. amphioxeia, we have sequenced and analyzed its plastid genome. The plastid genome sequence of T. amphioxeia is similar to that of Rhodomonas salina, and they share significant synteny. This sequence exhibits less similarity to that of Guillardia theta, the representative plastid genome of photosynthetic cryptophytes. The gene content and order of the three photosynthetic cryptomonad plastid genomes studied is highly conserved. The plastid genome of T. amphioxeia is composed of 129,772 bp and includes 143 protein-coding genes, 2 rRNA operons and 30 tRNA sequences. The DNA polymerase III gene (dnaX) was most likely acquired via lateral gene transfer (LGT) from a firmicute bacterium, identical to what occurred in R. salina. On the other hand, the psbN gene was independently encoded by the plastid genome without a reverse transcriptase gene as an intron. To clarify the phylogenetic relationships of the algae with red-algal derived plastids, phylogenetic analyses of 32 taxa were performed, including three previously sequenced cryptophyte plastid genomes containing 93 protein-coding genes. The stramenopiles were found to have branched out from the Chromista taxa (cryptophytes, haptophytes, and stramenopiles), while the cryptophytes and haptophytes were consistently grouped into sister relationships with high resolution.
authors.affiliation: Department of Biology, Chungnam National University, Daejeon, Korea.
authors.forename: Jong Im
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon, Korea.
authors.forename: Hwan Su
authors.initials: HS
authors.lastname: Yoon
authors.affiliation: Department of Computer Science, Gangneung-Wonju National University, Wonju, Korea.
authors.forename: Gangman
authors.initials: G
authors.lastname: Yi
authors.affiliation: Department of Marine Biotechnology, Kunsan National University, Kunsan, Korea.
authors.forename: Hyung Seop
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Marine Biotechnology, Kunsan National University, Kunsan, Korea.
authors.forename: Wonho
authors.initials: W
authors.lastname: Yih
authors.affiliation: Department of Biology, Chungnam National University, Daejeon, Korea.
authors.forename: Woongghi
authors.initials: W
authors.lastname: Shin
mesh_terms: D060365:Chloroplast Proteins / Q000235:genetics; D044785:Cryptophyta / Q000235:genetics*; D018742:DNA, Chloroplast / Q000737:chemistry / Q000235:genetics; D004270:DNA, Circular / Q000737:chemistry / Q000235:genetics; D023061:Gene Order; D022761:Gene Transfer, Horizontal; D061125:Genes, Chloroplast / Q000235:genetics*; D054627:Genome, Plastid / Q000235:genetics*; D010788:Photosynthesis / Q000235:genetics; D045331:Photosystem I Protein Complex / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000235:genetics; D010802:Phylogeny; D018087:Plastids / Q000145:classification / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D060365:Chloroplast Proteins; D018742:DNA, Chloroplast; D004270:DNA, Circular; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex