title: Recharacterization of Chlamydomonas reinhardtii and its relatives with new isolates from Japan.
abstract: Chlamydomonas reinhardtii P. A. Dang. (Volvocales, Chlorophyceae) is one of the most intensely studied algae, and its whole genome was sequenced. Although this species was originally described based on materials from France and is often referred to as a cosmopolitan species, all culture strains available today have been isolated from eastern North America. The distinctions with similar and/or closely related species, such as Chlamydomonas globosa J. Snow and Chlamydomonas orbicularis E. G. Pringsh., are also contentious. In this study, new strains of C. reinhardtii and C. globosa were isolated from Japan and compared with several strains similar to C. reinhardtii. Based on the morphological, genealogical, phylogenetical, and mating studies including the new Japanese strains, the circumscription of C. reinhardtii was clarified. C. reinhardtii was most closely related to C. globosa, and they were shown to be different species. Although C. reinhardtii was similar to C. orbicularis, the authentic strain of C. orbicularis was morphologically distinguishable and phylogenetically distant from C. reinhardtii. Discovery of the Japanese strains of C. reinhardtii supports the cosmopolitan distribution of this species. Based on Japanese strains and/or strains from other countries, emended descriptions of C. reinhardtii, C. globosa, and C. orbicularis are given.
authors.affiliation: Institute for Advanced Biosciences, Keio University, Yamagata, Japan. naktak@ttck.keio.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakada
authors.forename: Haruka
authors.initials: H
authors.lastname: Shinkawa
authors.forename: Takuro
authors.initials: T
authors.lastname: Ito
authors.forename: Masaru
authors.initials: M
authors.lastname: Tomita
mesh_terms: D001499:Bayes Theorem; D016825:Chlamydomonas reinhardtii / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D007564:Japan; D008853:Microscopy; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D012340:RNA, Ribosomal, 5.8S