A new marine prasinophyte genus alternates between a flagellate and a dominant benthic stage with microrhizoids for adhesion
© 2019 Phycological Society of America.
| Veröffentlicht in: | Journal of phycology. - 1966. - 55(2019), 6 vom: 17. Dez., Seite 1210-1225 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
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| Zugriff auf das übergeordnete Werk: | Journal of phycology |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Microrhizoidea Chlorophyta Dolichomastigales Mamiellophyceae basal bodies environmental sequences microrhizoids molecular phylogeny |
| Zusammenfassung: | © 2019 Phycological Society of America. Prasinophytes (Chlorophyta) are a diverse, paraphyletic group of planktonic microalgae for which benthic species are largely unknown. Here, we report a sand-dwelling, marine prasinophyte with several novel features observed in clonal cultures established from numerous locations around Australia. The new genus and species, which we name Microrhizoidea pickettheapsiorum (Mamiellophyceae), alternates between a benthic palmelloid colony, where cell division occurs, and a planktonic flagellate. Flagellates are short lived, settle and quickly resorb their flagella, the basal bodies then nucleate novel tubular appendages, termed "microrhizoids", that lack an axoneme and function to anchor benthic cells to the substratum. To our knowledge, microrhizoids have not been observed in any other green alga or protist, are slightly smaller in diameter than flagella, generally contain nine microtubules, are long (3-5 times the length of flagella) and are not encased in scales. Following settlement, cell divisions result in a loose, palmelloid colony, each cell connected to the substratum by two microrhizoids. Flagellates are round to bean-shaped with two long, slightly uneven flagella. Both benthic cells and flagellates, along with their flagella, are encased in thin scales. Phylogenies based on the complete chloroplast genome of Microrhizoidea show that it is clearly a member of the Mamiellophyceae, most closely related to Dolichomastix tenuilepsis. More taxon-rich phylogenetic analyses of the 18S rRNA gene, including metabarcodes from the Tara Oceans and Ocean Sampling Day projects, confidently show the distinctive nature of Microrhizoidea, and that the described biodiversity of the Mamiellophyceae is a fraction of its real biodiversity. The discovery of a largely benthic prasinophyte changes our perspective on this group of algae and, along with the observation of other potential benthic lineages in environmental sequences, illustrates that benthic habitats can be a rich ground for algal biodiscovery |
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| Beschreibung: | Date Completed 08.05.2020 Date Revised 08.05.2020 published: Print-Electronic GENBANK: MN056945-8, MN056173 CommentIn: J Phycol. 2019 Dec;55(6):1208-1209. - PMID 31784995 Citation Status MEDLINE |
| ISSN: | 1529-8817 |
| DOI: | 10.1111/jpy.12909 |