title: EVOLUTIONARY ANALYSES OF THE NUCLEAR-ENCODED PHOTOSYNTHETIC GENE psbO FROM TERTIARY PLASTID-CONTAINING ALGAE IN DINOPHYTA(1).
abstract: Although the dinophytes generally possess red-algal-derived secondary plastids, tertiary plastids originating from haptophyte and diatom ancestors are recognized in some lineages within the Dinophyta. However, little is known about the nuclear-encoded genes of plastid-targeted proteins from the dinophytes with diatom-derived tertiary plastids. We analyzed the sequences of the nuclear psbO gene encoding oxygen-evolving enhancer protein from various algae with red-algal-derived secondary and tertiary plastids. Based on our sequencing of 10 new genes and phylogenetic analysis of PsbO amino acid sequences from a wide taxon sampling of red algae and organisms with red-algal-derived plastids, dinophytes form three separate lineages: one composed of peridinin-containing species with secondary plastids, and the other two having haptophyte- or diatom-derived tertiary plastids and forming a robust monophyletic group with haptophytes and diatoms, respectively. Comparison of the N-terminal sequences of PsbO proteins suggests that psbO genes from a dinophyte with diatom-derived tertiary plastids (Kryptoperidinium) encode proteins that are targeted to the diatom plastid from the endosymbiotic diatom nucleus as in the secondary phototrophs, whereas the fucoxanthin-containing dinophytes (Karenia and Karlodinium) have evolved an additional system of psbO genes for targeting the PsbO proteins to their haptophyte-derived tertiary plastids from the host dinophyte nuclei.
authors.affiliation: Graduate School of Science and Engineering, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 Japan Department of Biology, Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Yokoyama
authors.affiliation: Graduate School of Science and Engineering, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 Japan Department of Biology, Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Takahashi
authors.affiliation: Graduate School of Science and Engineering, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 Japan Department of Biology, Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hironao
authors.initials: H
authors.lastname: Kataoka
authors.affiliation: Graduate School of Science and Engineering, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 Japan Department of Biology, Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Graduate School of Science and Engineering, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 Japan Department of Biology, Faculty of Science, Yamagata University, Kojirakawa 1-4-12, Yamagata 990-8560, Japan Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Nozaki
keywords: Dinophyta; Haptophyta; N-terminal region; diatoms; endosymbiosis; phylogeny; plastid; psbO genes