title: Soft coral Sarcophyton (Cnidaria: Anthozoa: Octocorallia) species diversity and chemotypes.
abstract: Research on the soft coral genus Sarcophyton extends over a wide range of fields, including marine natural products and the isolation of a number of cembranoid diterpenes. However, it is still unknown how soft corals produce this diverse array of metabolites, and the relationship between soft coral diversity and cembranoid diterpene production is not clear. In order to understand this relationship, we examined Sarcophyton specimens from Okinawa, Japan, by utilizing three methods: morphological examination of sclerites, chemotype identification, and phylogenetic examination of both Sarcophyton (utilizing mitochondrial protein-coding genes MutS homolog: msh1) and their endosymbiotic Symbiodinium spp. (utilizing nuclear internal transcribed spacer of ribosomal DNA: ITS- rDNA). Chemotypes, molecular phylogenetic clades, and sclerites of Sarcophyton trocheliophorum specimens formed a clear and distinct group, but the relationships between chemotypes, molecular phylogenetic clade types and sclerites of the most common species, Sarcophyton glaucum, was not clear. S. glaucum was divided into four clades. A characteristic chemotype was observed within one phylogenetic clade of S. glaucum. Identities of symbiotic algae Symbiodinium spp. had no apparent relation to chemotypes of Sarcophyton spp. This study demonstrates that the complex results observed for S. glaucum are due to the incomplete and complex taxonomy of this species group. Our novel method of identification should help contribute to classification and taxonomic reassessment of this diverse soft coral genus.
authors.affiliation: Graduate School of Science and Engineering, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Satoe
authors.initials: S
authors.lastname: Aratake
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Tomura
authors.forename: Seikoh
authors.initials: S
authors.lastname: Saitoh
authors.forename: Ryouma
authors.initials: R
authors.lastname: Yokokura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kawanishi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Shinjo
authors.forename: James Davis
authors.initials: JD
authors.lastname: Reimer
authors.forename: Junichi
authors.initials: J
authors.lastname: Tanaka
authors.forename: Hideaki
authors.initials: H
authors.lastname: Maekawa
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D002467:Cell Nucleus / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004141:Dinoflagellida / Q000145:classification / Q000235:genetics*; D004224:Diterpenes / Q000737:chemistry / Q000378:metabolism*; D014644:Genetic Variation; D007564:Japan; D008855:Microscopy, Electron, Scanning; D024101:Mitochondrial Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013559:Symbiosis
chemical_list: D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D004224:Diterpenes; D024101:Mitochondrial Proteins