title: Characterization of MADS-box genes in charophycean green algae and its implication for the evolution of MADS-box genes.
abstract: The MADS-box genes of land plants are extensively diverged to form a superfamily and are important in various aspects of development including the specification of floral organs as homeotic selector genes. The closest relatives of land plants are the freshwater green algae charophyceans. To study the origin and evolution of land plant MADS-box genes, we characterized these genes in three charophycean green algae: the stonewort Chara globularis, the coleochaete Coleochaete scutata, and the desmid Closterium peracerosum-strigosum-littorale complex. Phylogenetic analyses suggested that MADS-box genes diverged extensively in the land plant lineage after the separation of charophyceans from land plants. The stonewort C. globularis mRNA was specifically detected in the oogonium and antheridium together with the egg and spermatozoid during their differentiation. The expression of the C. peracerosum-strigosum-littorale-complex gene increased when vegetative cells began to differentiate into gametangial cells and decreased after fertilization. These expression patterns suggest that the precursors of land plant MADS-box genes originally functioned in haploid reproductive cell differentiation and that the haploid MADS-box genes were recruited into a diploid generation during the evolution of land plants.
authors.affiliation: Department of Multi-Disciplinary Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Mitsuyasu
authors.initials: M
authors.lastname: Hasebe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sekimoto
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Nishiyama
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kitani
authors.forename: Katrin
authors.initials: K
authors.lastname: Henschel
authors.forename: Thomas
authors.initials: T
authors.lastname: Münster
authors.forename: Günter
authors.initials: G
authors.lastname: Theissen
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Nozaki
authors.forename: Motomi
authors.initials: M
authors.lastname: Ito
mesh_terms: D020418:Algal Proteins / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D044784:Chara / Q000235:genetics; D044522:Characeae / Q000235:genetics*; D000460:Chlorophyta / Q000235:genetics*; D048028:DNA, Algal / Q000235:genetics*; D019143:Evolution, Molecular; D005091:Exons; D007438:Introns; D026161:MADS Domain Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D020418:Algal Proteins; D048028:DNA, Algal; D026161:MADS Domain Proteins