EFOR Paris January 2010 Moreau H [Mode de compatibilité]

CNRS CNRS Dépasser Dépasser les les frontières
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Phytoplankton model organisms
Hervé Moreau. h.moreau@obs-banyuls.fr
Oceanological Observatory of Banyuls (OOB)
CNRS - UPMC
Importance and diversity of phytoplankton
Exploration of the diversity of phytoplankton
Ressources

Marine environment: distribution of chlorophyll a in oceans
Highly dynamic populations: Oceanic phytoplankton renewed weekly

The crown of eukaryotes
Keeling et al. 2005

Filtration of sea water
0.01-0.45, 0.2-0.8 or 0.8-2.0 µm
Amplification 16/18S
Diversity of species
Exploration of phytoplankton
Metagenomics
Establishment of phtoplankton
model species
Total genomic DNA extraction
Shotgun sequencing
Environmental gene signature

Global Ocean Sampling
Data available 2003-2006. Camera
database (Community
Cyberinfrastructure for
Advanced Marine Microbial
Ecology Research and Analysis):
: http://camera.calit2.net/
2003 : Sargasso sea
2004-2006 : Around global ocean + equatorial,
surface sampling (PLoS Biol 2007)
2007-2008 : Extreme environments (hot springs,
high salinity, polar ices)
2009-2010 : English channel, Baltic sea,
Mediterranean, Black sea
European TARA cruise 2009-2012

Photosynthetic cyanobacteria
Prochlorococcus and Synechococcus
- Most abundant pico-phytoplankton
species in oceans
- Prochlorococcus dominant in
oligotropic areas
- Synechococcus more coastal
- Many strains and ecotype sequenced

Thalassiosira pseudonana
1 μm
Importance in global carbon cycling
Thalassiosira is a cosmopolitan genus
T. pseudonana used as a physiological model
Small genome (32 Mb)
Fragiliaropsis
Pseudonitzschia
Cyclotella meneghiniana
Seminavis robusta
Diatoms
Phaeodactylum tricornutum
4 μm
4 μm 4 μm
Advanced resources for reverse genetics
10 Accessions available from different locations
110,000 ESTs available from different conditions
Small genome (27 Mb)
Courtesy Chris Bowler

Haptophytes
Emiliania huxleyi Phaeocystis antarctica
Picture from J. Young, London Picture from JGI web site
It is the most abundant global coccolithophore,
sometimes occurring in massive blooms.
It represents an important component of the marine
carbon cycle as it exports calcium carbonate from the
surface of the ocean to the bottom.
The polar algae Phaeocystis antarctica is a key
member of the phytoplankton community in the
Southern Ocean where it plays a major role in global
carbon and sulfur cycles.

Prasinophytes - Mamiellales
Ostreococcus
From Chrétiennot-Dinet et al. (1995)
1 µm
From Guillou et al. (2004)
Micromonas
Bathycoccus
1 µm
Courtesy MJ Dinet. N°170650704
From S. Sym and D. Keats; http://hypnea.botany.uwc.ac.za/
Picoeukaryotes: size < 2-3 µm
Small genome size (12-25 Mb)

Global amino acid identity between the three Ostreococcus

S. bayanus
82%
S. paradoxus
91%
Saccharomyces cerevisiae
YEAST PLANTAE CHORDATA
Kluyveromyces lactis
54%
Candida glabrata
58%
90
100
70
80
60
50
Chlamydomonas
reinhardtii 44%
Micromonas
pusilla 53%
O. tauri
68%
O. sp.
71%
Ostreococcus
lucimarinus
50
60
Ciona intestinalis
47%
70
80
Tetraodon nigroviridis
62%
90
100
Gallus gallus
74%
Mus musculus
85%
Pan troglodytes
98%
Homo sapiens

Volvox and Ulva, colonial and multicell
green organisms
From Wim van Egmond, The Netherlands
ttp://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artdec03/volvox.html
http://www.mbari.org/staff/conn/botany/greens/anna/frontpages/morphol.htm
Chlorella (2) Trebouxiophyceae
Dunaliella Chlorophyceae
Coccomyxa Trebouxiophyceae (lichen)
Botryococcus Trebouxiophyceae
Ostreococcus (3 + 20) Prasinophyceae
Micromonas (2) Prasinophyceae
Bathycoccus Prasinophyceae
Chlamydomonas Chlorophyceae
Volvox Chlorophyceae
Keeling et al. 2005
Primary endosymbiosis
Chondrus
Cyanidioschyzon
Ulva
Volvox
Chlorella
Chlamydomonas
Ostreococcus
Micromonas
Arabidopsis
Rice
Poplar
Alfafa
Others
Physcomitrella

Isolation of 18 new strains of O.tauri
Using the 18S rDNA sequence for species identification (100% Id)
Th
au
Bages-Sigean
Lapal
me
Leuca
te
MOL
SOL
A
A B90

Selection of « neutral » regions in the
O. tauri genome
ƒ selection of 4 around 300 bp “Tail to Tail” intergenic regions on
chromosomes 1 and 18

Frequency of sexual reproduction in the marine environment

Ressources
The CCMP is the national marine phytoplankton collection, and it is an integral part of Bigelow Laboratory for Ocean
Sciences. The CCMP maintains over 2500 strains from around the world, the preponderance are marine phytoplankters but
we also have benthic, macrophytic, freshwater and heterotrophic organisms
ATCC is a global nonprofit bioresource center (BRC) and research organization that provides biological products
The European Culture Collections' Organisation (ECCM) is a European non-profit organisation which promotes
the collaboration and exchange of ideas and information on all aspects of culture collection activity. Corporate members
of ECCM are microbial resource centres of countries with microbiological societies affiliated to the Federation of the
European Microbiological Societies (FEMS).
Culture Collection of Algae and Protozoa (CCAP) at Oban (UK) maintains a collection of over 2000 strains
of algae and protozoa
The Roscoff Culture Collection (RCC) maintains about 1500 strains of marine phytoplankton with emphasis on
picoplankton (in particular Prochlorococcus and Synechococcus), picoeucaryotes and coccolithophorids. The collection
is part of the ASSEMBLE EU FP7 research infrastructure network which has been recently launched
Stazione Zoologica Anthon Dohrn Naples Italy harbours the Taxonomic Identification of Marine Plankton (TIMP) service
CAMERA - Community Cyberinfrastructure for Advanced Marine Microbial Ecology Research and Analysis
The aim of this project is to serve the needs of the microbial ecology research community by creating a rich, distinctive
data repository and a bioinformatics tools resource that will address many of the unique challenges of metagenomic analysis.

LES ENJEUX DE LA CONSERVATION DES
SOUCHES DE PHYTOPLANCTON
- Augmenter les capacités des collections
- Assurer des sauvegardes indépendantes
- Développer la cryopréservation
- Développer des méthodes de cultures pour les « incultivables »