Gymnoxanthella radiolariae gen. et sp. nov. (Dinophyceae), a dinoflagellate symbiont from solitary polycystine radiolarians

© 2016 Phycological Society of America.

Détails bibliographiques
Publié dans:Journal of phycology. - 1966. - 52(2016), 1 vom: 18. Feb., Seite 89-104
Auteur principal: Yuasa, Tomoko (Auteur)
Autres auteurs: Horiguchi, Takeo, Mayama, Shigeki, Takahashi, Osamu
Format: Article en ligne
Langue:English
Publié: 2016
Accès à la collection:Journal of phycology
Sujets:Journal Article Research Support, Non-U.S. Gov't Gymnoxanthella radiolariae gen. et sp. nov. Zooxanthella nutricula dinoflagellate molecular phylogeny radiolarians symbiont DNA, Ribosomal
Description
Résumé:© 2016 Phycological Society of America.
The symbiotic dinoflagellate Gymnoxanthella radiolariae T. Yuasa et T. Horiguchi gen. et sp. nov. isolated from polycystine radiolarians is described herein based on light, scanning and transmission electron microscopy as well as molecular phylogenetic analyses of SSU and LSU rDNA sequences. Motile cells of G. radiolariae were obtained in culture, and appeared to be unarmored. The cells were 9.1-11.4 μm long and 5.7-9.4 μm wide, and oval to elongate oval in the ventral view. They possessed an counterclockwise horseshoe-shaped apical groove, a nuclear envelope with vesicular chambers, cingulum displacement with one cingulum width, and the nuclear fibrous connective; all of these are characteristics of Gymnodinium sensu stricto (Gymnodinium s.s.). Molecular phylogenetic analyses also indicated that G. radiolariae belongs to the clade of Gymnodinium s.s. However, in our molecular phylogenetic trees, G. radiolariae was distantly related to Gymnodinium fuscum, the type species of Gymnodinium. Based on the consistent morphological, genetic, and ecological divergence of our species with the other genera and species of Gymnodinium s.s., we considered it justified to erect a new, separate genus and species G. radiolariae gen. et sp. nov. As for the peridinioid symbiont of radiolarians, Brandtodinium has been erected as a new genus instead of Zooxanthella, but the name Zooxanthella is still valid. Brandtodinium is a junior synonym of Zooxanthella. Our results suggest that at least two dinoflagellate symbiont species, peridinioid Zooxanthella nutricula and gymnodinioid G. radiolariae, exist in radiolarians, and that they may have been mixed and reported as "Z. nutricula" since the 19th century
Description:Date Completed 10.01.2017
Date Revised 11.01.2017
published: Print-Electronic
Citation Status MEDLINE
ISSN:1529-8817
DOI:10.1111/jpy.12371