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Recent radiation in a marine and freshwater dinoflagellate species flock.

Annenkova, Nataliia LU ; Hansen, Gert; Moestrup, Øjvind and Rengefors, Karin LU (2015) In The Isme Journal 9(8). p.1821-1834
Abstract
Processes of rapid radiation among unicellular eukaryotes are much less studied than among multicellular organisms. We have investigated a lineage of cold-water microeukaryotes (protists) that appear to have diverged recently. This lineage stands in stark contrast to known examples of phylogenetically closely related protists, in which genetic difference is typically larger than morphological differences. We found that the group not only consists of the marine-brackish dinoflagellate species Scrippsiella hangoei and the freshwater species Peridinium aciculiferum as discovered previously but also of a whole species flock. The additional species include Peridinium euryceps and Peridinium baicalense, which are restricted to a few lakes, in... (More)
Processes of rapid radiation among unicellular eukaryotes are much less studied than among multicellular organisms. We have investigated a lineage of cold-water microeukaryotes (protists) that appear to have diverged recently. This lineage stands in stark contrast to known examples of phylogenetically closely related protists, in which genetic difference is typically larger than morphological differences. We found that the group not only consists of the marine-brackish dinoflagellate species Scrippsiella hangoei and the freshwater species Peridinium aciculiferum as discovered previously but also of a whole species flock. The additional species include Peridinium euryceps and Peridinium baicalense, which are restricted to a few lakes, in particular to the ancient Lake Baikal, Russia, and freshwater S. hangoei from Lake Baikal. These species are characterized by relatively large conspicuous morphological differences, which have given rise to the different species descriptions. However, our scanning electron microscopic studies indicate that they belong to a single genus according to traditional morphological characterization of dinoflagellates (thecal plate patterns). Moreover, we found that they have identical SSU (small subunit) rDNA fragments and distinct but very small differences in the DNA markers LSU (large subunit) rDNA, ITS2 (internal transcribed spacer 2) and COB (cytochrome b) gene, which are used to delineate dinoflagellates species. As some of the species co-occur, and all four have small but species-specific sequence differences, we suggest that these taxa are not a case of phenotypic plasticity but originated via recent adaptive radiation. We propose that this is the first clear example among free-living microeukaryotes of recent rapid diversification into several species followed by dispersion to environments with different ecological conditions.The ISME Journal advance online publication, 20 January 2015; doi:10.1038/ismej.2014.267. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
in
The Isme Journal
volume
9
issue
8
pages
1821 - 1834
publisher
Nature Publishing Group
external identifiers
  • pmid:25603395
  • wos:000358260100012
  • scopus:84937730229
ISSN
1751-7362
DOI
10.1038/ismej.2014.267
project
CAnMove
language
English
LU publication?
yes
id
10ba770e-85e3-40fa-ad43-bf657a0a7070 (old id 5040132)
date added to LUP
2015-02-26 13:39:24
date last changed
2017-10-08 03:02:06
@article{10ba770e-85e3-40fa-ad43-bf657a0a7070,
  abstract     = {Processes of rapid radiation among unicellular eukaryotes are much less studied than among multicellular organisms. We have investigated a lineage of cold-water microeukaryotes (protists) that appear to have diverged recently. This lineage stands in stark contrast to known examples of phylogenetically closely related protists, in which genetic difference is typically larger than morphological differences. We found that the group not only consists of the marine-brackish dinoflagellate species Scrippsiella hangoei and the freshwater species Peridinium aciculiferum as discovered previously but also of a whole species flock. The additional species include Peridinium euryceps and Peridinium baicalense, which are restricted to a few lakes, in particular to the ancient Lake Baikal, Russia, and freshwater S. hangoei from Lake Baikal. These species are characterized by relatively large conspicuous morphological differences, which have given rise to the different species descriptions. However, our scanning electron microscopic studies indicate that they belong to a single genus according to traditional morphological characterization of dinoflagellates (thecal plate patterns). Moreover, we found that they have identical SSU (small subunit) rDNA fragments and distinct but very small differences in the DNA markers LSU (large subunit) rDNA, ITS2 (internal transcribed spacer 2) and COB (cytochrome b) gene, which are used to delineate dinoflagellates species. As some of the species co-occur, and all four have small but species-specific sequence differences, we suggest that these taxa are not a case of phenotypic plasticity but originated via recent adaptive radiation. We propose that this is the first clear example among free-living microeukaryotes of recent rapid diversification into several species followed by dispersion to environments with different ecological conditions.The ISME Journal advance online publication, 20 January 2015; doi:10.1038/ismej.2014.267.},
  author       = {Annenkova, Nataliia and Hansen, Gert and Moestrup, Øjvind and Rengefors, Karin},
  issn         = {1751-7362},
  language     = {eng},
  number       = {8},
  pages        = {1821--1834},
  publisher    = {Nature Publishing Group},
  series       = {The Isme Journal},
  title        = {Recent radiation in a marine and freshwater dinoflagellate species flock.},
  url          = {http://dx.doi.org/10.1038/ismej.2014.267},
  volume       = {9},
  year         = {2015},
}