title: Genome sequence of the ultrasmall unicellular red alga Cyanidioschyzon merolae 10D.
abstract: Small, compact genomes of ultrasmall unicellular algae provide information on the basic and essential genes that support the lives of photosynthetic eukaryotes, including higher plants. Here we report the 16,520,305-base-pair sequence of the 20 chromosomes of the unicellular red alga Cyanidioschyzon merolae 10D as the first complete algal genome. We identified 5,331 genes in total, of which at least 86.3% were expressed. Unique characteristics of this genomic structure include: a lack of introns in all but 26 genes; only three copies of ribosomal DNA units that maintain the nucleolus; and two dynamin genes that are involved only in the division of mitochondria and plastids. The conserved mosaic origin of Calvin cycle enzymes in this red alga and in green plants supports the hypothesis of the existence of single primary plastid endosymbiosis. The lack of a myosin gene, in addition to the unexpressed actin gene, suggests a simpler system of cytokinesis. These results indicate that the C. merolae genome provides a model system with a simple gene composition for studying the origin, evolution and fundamental mechanisms of eukaryotic cells.
authors.affiliation: Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. mzaki@biol.s.u-tokyo.ac.jp
authors.forename: Motomichi
authors.initials: M
authors.lastname: Matsuzaki
authors.forename: Osami
authors.initials: O
authors.lastname: Misumi
authors.forename: Tadasu
authors.initials: T
authors.lastname: Shin-I
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Maruyama
authors.forename: Manabu
authors.initials: M
authors.lastname: Takahara
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Miyagishima
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Mori
authors.forename: Keiji
authors.initials: K
authors.lastname: Nishida
authors.forename: Fumi
authors.initials: F
authors.lastname: Yagisawa
authors.forename: Keishin
authors.initials: K
authors.lastname: Nishida
authors.forename: Yamato
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Nakao
authors.forename: Tamaki
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yu
authors.initials: Y
authors.lastname: Momoyama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Higashiyama
authors.forename: Ayumi
authors.initials: A
authors.lastname: Minoda
authors.forename: Masako
authors.initials: M
authors.lastname: Sano
authors.forename: Hisayo
authors.initials: H
authors.lastname: Nomoto
authors.forename: Kazuko
authors.initials: K
authors.lastname: Oishi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Hayashi
authors.forename: Fumiko
authors.initials: F
authors.lastname: Ohta
authors.forename: Satoko
authors.initials: S
authors.lastname: Nishizaka
authors.forename: Shinobu
authors.initials: S
authors.lastname: Haga
authors.forename: Sachiko
authors.initials: S
authors.lastname: Miura
authors.forename: Tomomi
authors.initials: T
authors.lastname: Morishita
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kabeya
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Terasawa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Shuichi
authors.initials: S
authors.lastname: Asakawa
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Takano
authors.forename: Niji
authors.initials: N
authors.lastname: Ohta
authors.forename: Haruko
authors.initials: H
authors.lastname: Kuroiwa
authors.forename: Kan
authors.initials: K
authors.lastname: Tanaka
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Shimizu
authors.forename: Sumio
authors.initials: S
authors.lastname: Sugano
authors.forename: Naoki
authors.initials: N
authors.lastname: Sato
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Nozaki
authors.forename: Naotake
authors.initials: N
authors.lastname: Ogasawara
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kohara
authors.forename: Tsuneyoshi
authors.initials: T
authors.lastname: Kuroiwa
mesh_terms: D000199:Actins / Q000235:genetics; D020418:Algal Proteins / Q000145:classification / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics; D002875:Chromosomes / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D019143:Evolution, Molecular; D016678:Genome; D023281:Genomics; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D018087:Plastids / Q000235:genetics / Q000502:physiology; D000461:Rhodophyta / Q000166:cytology / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D000199:Actins; D020418:Algal Proteins; D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal