TY - JOUR
T1 - Origin and evolution of the colonial Volvocales (Chlorophyceae) as inferred from multiple, chloroplast gene sequences
AU - Nozaki, Hisayoshi
AU - Misawa, Kazuharu
AU - Kajita, Tadashi
AU - Kato, Masahiro
AU - Nohara, Seiichi
AU - Watanabe, Makoto M.
N1 - Funding Information:
We are grateful to anonymous reviewers who kindly and dramatically improved the text. This study was in part supported by a Grant-in-Aid for Scientific Research (No. 11440241 to H.N.) from the Ministry of Education, Science and Culture, Japan, and by a Grant-in-Aid for a Research Project on Conservation Methods for Subtropical Island Ecosystems (to S.N.) from the Environmental Agency, Japan.
PY - 2000
Y1 - 2000
N2 - A combined data set of DNA sequences (6021 bp) from five protein-coding genes of the chloroplast genome (rbcL, atpB, psaA, psaB, and psbC genes) were analyzed for 42 strains representing 30 species of the colonial Volvocales (Volvox and its relatives) and 5 related species of green algae to deduce robust phylogenetic relationships within the colonial green flagellates. The 4-celled family Tetrabaenaceae was robustly resolved as the most basal group within the colonial Volvocales. The sequence data also suggested that all five volvocacean genera with 32 or more cells in a vegetative colony (all four of the anisogamous/oogamous genera, Eudorina, Platydorina, Pleodorina, and Volvox, plus the isogamous genus Yamagishiella) constituted a large monophyletic group, in which 2 Pleodorina species were positioned distally to 3 species of Volvox. Therefore, most of the evolution of the colonial Volvocales appears to constitute a gradual progression in colonial complexity and in types of sexual reproduction, as in the traditional volvocine lineage hypothesis, although reverse evolution must be considered for the origin of certain species of Pleodorina. Data presented here also provide robust support for a monophyletic family Goniaceae consisting of two genera: Gonium and Astrephomene. (C) 2000 Academic Press.
AB - A combined data set of DNA sequences (6021 bp) from five protein-coding genes of the chloroplast genome (rbcL, atpB, psaA, psaB, and psbC genes) were analyzed for 42 strains representing 30 species of the colonial Volvocales (Volvox and its relatives) and 5 related species of green algae to deduce robust phylogenetic relationships within the colonial green flagellates. The 4-celled family Tetrabaenaceae was robustly resolved as the most basal group within the colonial Volvocales. The sequence data also suggested that all five volvocacean genera with 32 or more cells in a vegetative colony (all four of the anisogamous/oogamous genera, Eudorina, Platydorina, Pleodorina, and Volvox, plus the isogamous genus Yamagishiella) constituted a large monophyletic group, in which 2 Pleodorina species were positioned distally to 3 species of Volvox. Therefore, most of the evolution of the colonial Volvocales appears to constitute a gradual progression in colonial complexity and in types of sexual reproduction, as in the traditional volvocine lineage hypothesis, although reverse evolution must be considered for the origin of certain species of Pleodorina. Data presented here also provide robust support for a monophyletic family Goniaceae consisting of two genera: Gonium and Astrephomene. (C) 2000 Academic Press.
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U2 - 10.1006/mpev.2000.0831
DO - 10.1006/mpev.2000.0831
M3 - Article
C2 - 11083939
AN - SCOPUS:0033677765
SN - 1055-7903
VL - 17
SP - 256
EP - 268
JO - Molecular Phylogenetics and Evolution
JF - Molecular Phylogenetics and Evolution
IS - 2
ER -