Format

Send to

Choose Destination
ISME J. 2015 Jun;9(6):1365-77. doi: 10.1038/ismej.2014.221. Epub 2014 Dec 2.

Life-cycle modification in open oceans accounts for genome variability in a cosmopolitan phytoplankton.

Author information

1
1] Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile [2] UMI 3614, Evolutionary Biology and Ecology of Algae, CNRS, UPMC Sorbonne Universités, PUCCh, UACH, Station Biologique de Roscoff, Roscoff, France [3] Instituto Milenio de Oceanografía, Concepción, Chile [4] CNRS UMR 7144 and UMPC, Evolution of Pelagic Ecosystems and Protists (EPEP), CNRS, UPMC, Station Biologique de Roscoff, Roscoff, France.
2
Alfred Wegener Institute Helmhotz Centre for Polar and Marine Research, Bremerhaven, Germany.
3
1] Institute for Chemical Research, Kyoto University, Kyoto, Japan [2] CNRS, Aix-Marseille Université, Laboratoire Information Génomique et Structurale (UMR 7256), Mediterranean Institute of Microbiology (FR 3479), Marseille, France.
4
CNRS-UMPC, FR2424, Roscoff Culture Collection, Station Biologique de Roscoff, Roscoff, France.
5
Marine Biological Association of the UK, The Laboratory, Citadel Hill, Plymouth, UK.
6
CNRS UMR 7144 and UMPC, Evolution of Pelagic Ecosystems and Protists (EPEP), CNRS, UPMC, Station Biologique de Roscoff, Roscoff, France.
7
CEA Genoscope, 2 rue Gaston Crémieux, Evry, France.
8
CNRS, Aix-Marseille Université, Laboratoire Information Génomique et Structurale (UMR 7256), Mediterranean Institute of Microbiology (FR 3479), Marseille, France.
9
Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
10
1] Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile [2] UMI 3614, Evolutionary Biology and Ecology of Algae, CNRS, UPMC Sorbonne Universités, PUCCh, UACH, Station Biologique de Roscoff, Roscoff, France.
11
Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.

Abstract

Emiliania huxleyi is the most abundant calcifying plankton in modern oceans with substantial intraspecific genome variability and a biphasic life cycle involving sexual alternation between calcified 2N and flagellated 1N cells. We show that high genome content variability in Emiliania relates to erosion of 1N-specific genes and loss of the ability to form flagellated cells. Analysis of 185 E. huxleyi strains isolated from world oceans suggests that loss of flagella occurred independently in lineages inhabiting oligotrophic open oceans over short evolutionary timescales. This environmentally linked physiogenomic change suggests life cycling is not advantageous in very large/diluted populations experiencing low biotic pressure and low ecological variability. Gene loss did not appear to reflect pressure for genome streamlining in oligotrophic oceans as previously observed in picoplankton. Life-cycle modifications might be common in plankton and cause major functional variability to be hidden from traditional taxonomic or molecular markers.

PMID:
25461969
PMCID:
PMC4438323
DOI:
10.1038/ismej.2014.221
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center