Diversity of marine...
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Images de Plankton@net Diversity of marine phytoplankton Nathalie Simon January 2012 – UE EPHYBIO – Master 2
Transcript of Diversity of marine...
Images de Plankton@net
Diversity of marine phytoplankton
Nathalie Simon
January 2012 – UE EPHYBIO – Master 2
Ch a in Oceans
0.1
0.5
10
mg/m3
Phytoplankton : « wandering plants »
1% of Chl
on earth
45% of Net
Primary
Production
Enrichment in
inorganic C
Ci enrichment maintains excess C02 in oceans compared to atmosphere
(Ocean : 300 ppm more CO2)
Biological pump
Finlay, 2002
Pico-
(0,2-2 µm)
Nano-
(2-20 µm)
Micro-
(20-200 µm)Méso-
(200µm-2mm)
…plancton
Qqs mm
0,4 µm
Cyanobacteria
Cyanobacteria
-Unicellular, trichoms, filaments
-Bacterial Cellular Envelopp
-Thylacoïds concentric, Chl a, carotenes, phycobilisomes (except for few generasuch as Prochlorococcus)
-Genetic material: circular DNA, no histones
-Possibility for N2 fixation (hétérocystes)
-Gaz Vacuoles (plankton)
PE II
PE IAPC
PC
Liberton et al., 2006
100 nm
Synechocystis
Mb plasmique
Peptidoglucane
Mb externe
carboxysome
ribosome
glycogène
granule de cyanophycine
Cyanobacteria :
gram- Bacteria
Marine planktonic cyanobacteria: ~14 genera?
Trichodesmium
Richelia intracellularis ©LOB/K. Leblanc
©LOB/K. Leblanc
-Trichomes organised in filaments
-Blooms (tropics)
-atm N2 Fixation
- Symbiosis withdiatoms (Guinardia, Hemiaulus,…)
-Trichomes withheterocysts(Fixation N2
atm.)
(Photo by Dave Caron, Woods Hole Oceanographic Institution)
ProchlorococcusSynechococcus « Crocosphaera »
Unicellular
Antenna with
phycobilisomes Antenna with Divinyl Chla/b
Several genetic
cladesSeveral genetic
clades
Low genetic diversity
No N2 fixation N2 FixationNo N2 fixation
Antenna with
phycobilisomes
2 functionnal groups
1. Non diazotroph picocyanobacteria : major contribution to primary production in oligotrophic ocean (ex. adaptations : reducedsize)
2. Filamentous diazotrophs : More than ½ of N import in tropics.
Primitive organisms with characters similar to those of
PS Cyanobacteria p (-2,7 Billion years) are at the origin
of atmospheric oxygenation (-2,3 Billion years).
2 functionnal groups
1. Non diazotroph picocyanobacteria : major contribution to primary production in oligotrophic ocean (ex. adaptations : reducedsize)
2. Filamentous diazotrophs : More than ½ of N import in tropics.
Primitive organisms with characters similar to those of
PS Cyanobacteria p (-2,7 Ma y) are at the origin of
atmospheric oxygenation (-2,3 Ma ans), and are at the
origin of all plastids.
SynechococcusProchlorococcus
PhormidiumProchlorothrix
Leptolyngbya
Nostoc, Calothrix, Scytonema,
Anabaena, Cylindrospermum
Oscillatoria, Trichodesmium,
Microcoleus, Arthrospira, Lyngbya
Gloeothece, Gloeocapsa, Synechocystis
Microcystis, Pleurocapsa, Prochloron
PlastidsPseudanabaena
Limnothrix
Unicellulars thermophiles
Gloeobacter
Strains phylogenetically close to
Gloeobacter
Chamaesiphon
Turner (1997, 1999)
Plastids form a
monophyletic group
Cyano-
Bacteria
+
Plastids
rDNA 16S
Primary endosymbiosis
Photosynthesis acquired by
eukaryotes through
endosymbiosis
Plantae
Excavates
Eukaryotes consensus
phylogeny
Bauldauf 2008
Unikonts
Habrobia
SAR
Reviers 2011
Diatoms, dinoflagellates and
haptophytes (coccolithophores)
3 major groups of the micro-
and nano-phytoplankton
DiatomsBelong to Heterokonta (Stramenopiles)
Phylum Ochrophyta
40 % Of net Primary production by phytoplankton
40% of described species within phytoplankton
50 % of exported C
Microplankton (nanoplankton)
Lee (2008)
Chap 11 vidéo
-Photosynthetic, unicellular (forming
colonies)
-Frustule = silicified cell wall
-Brown plastids
-10 000 species (> 2000 marine
planktonic
-Ecologically diverse
-Fossils and geological formations
“diatomite” “tripoli” ou “kieselguhr”
Generalities about diatoms
Epitheca
Hypotheca
Epivalve
Cingular
band
Drawings from : W. Kooistra
Source : wikipedia
Frustule
Le frustule
Thalassiosira eccentrica Plankton@net
Vues valvaires Vue cingulaire
Les processus : projections à parois
silicifiées
Ornementations
Pores Areolae
Processus (projections de silice)
Van den Hoek, 1995
Chloroplast :
Envelop with 4 membranes
Groups of 3 thylacoïdes, lamella,
pyrénoïd(s) or not
Pigments : Chl a, c, fucoxanthin +
caroténoïds
Storage material:
Chrysolaminarin
polyphosphates
Lipid droplets
Origin of diatoms plastids
E I = Cyanobacteria
EII= Red algea
Moustafa et al. Science
2010 : Origin of diatoms
genes identified through
phylogenomics
(among genes identified as
originating from green or
red algae)
2 complete genomes
Plastid originates from a Iiary endosymbiosis with red algae
A Iiary endosymbiosis with a green algae could have left traces???
Radial Centrics
Stephanopyxis
Corethron
Coscinodiscus
Diapositive : W. Kooistra
Multi-polarCentrics
Chaetoceros
Thalassiosira
Odontella
Diapositive : W. Kooistra
Araphid Pennates
Fragilaria
Asterionella
Synedra
Licmophora
Diapositive : W. Kooistra
Raphid Pennates
Campylodiscus
Entomoneis
Pseudo-nitzschia
Diapositive : W. Kooistra
Araphid pennates
Raphid pennates
Radial centrics
Multi-polarcentrics
0.01
SSU
Diapositive : W. Kooistra
0
T
K
J
65
120
207
145
Tr
Calyptosporium, (Korea) Harwood et al., in prep.Radial centrics
Pyxidicula, (Germany) Rothpletz, 1896 Radial centrics
Antarctic ODP-Leg 693 Gersonde and Harwood, 1990Australia Nikolaev and Harwood, 1997Radial centrics and few multipolar
Presence of pennates without raphe
Presence of pennates with raphe
90
180
Frustules fossiles
De W. Kooistra modifiée
0.01
Planktonic diatoms
appeared several
times in evolution
Mobile on substrate
Benthic epiphytic
Modified from : W. Kooistra
Ancestral benthic life style
Few pennate
planktonic diatoms
© Jan Rines
Eucampia
Chaetoceros
Adaptations to live in the plankton
Chaetoceros et al.
Diapositive : W. Kooistra
Skeletonema
Thalassiosira
Adaptations to live in the plankton
Thalassiosirales
Diapositive : W. Kooistra
ThalassionemaAsterionellopsis
Asterionella
Thalassionema
Asterionella
Pseudo-nitzschia and Fragilariopsis
Asterionellopsis
Diapositive : W. Kooistra
Trades-off : selection /adaptation
Many opportinistic « bloomers »
Large vacuole
•Stocks of NO3-, PO42-
•Allows to lower the amount available
to competitors.
Frustule
• Protection against predation
• Flottability
DinoflagellatesAlveolata, Dinophyta
Dinophyceae
Important part of net primary production in the oceans
40% of marine phytoplankton species described
Nano - Microplankton
-Unicellular (may form colonies)
-Cell wall : Cellulose in alveoles
-2 flagella (transverse +
longitidinal)
-Brown, red, green plastids
-Taxonomic diversity: 5000
species (2000 planktonic
photosynthetic)
Epithèque
Epicône
Hypothèque, hypocône
D G
Vue ventrale
Alveoles with or without cellulose plaques
Naked / armored
From Lee (1989) and plankton@net
Alexandrium tamarense
Dinophysis acuta
Karenia brevis
Dinokont disposition
Flagella inserted ventraly, in silts
Modified from Lee, 1989
Karenia brevis
Peridinium cinctum
Longitudinal Fl.
(in sulcus)
Transverse Fl.
(in cingulum)
Ventral vue
Disposition « desmocontée »
2 flagelles à l’apex
Dorsal vue
Ultrastructure
Phycologia, mai 2004
Nucleus (condensed
chromosomes - Histones very
peculiar - ~100 x more DNA
than other euks)
Trichocyst
Chloroplasts – most frequent
Envelopp with 3 membranes, thylacoïds
by 3
Chl a, c, peridinin
Main storage: starch
Le dinokaryon, un noyau très particulier
Interphase
B : Corps basaux, K : kinétochores, C : Chromosomes, NM :
membrane nucléaire, Mt : Microtubules
Début division
Ségrégation des
chromosomes
(avec mise en place d’un
canal cytoplasmique)
Division du
noyau
RCC1488 : Lepidodinium chlorophorum (isolée par I. Probert en Manche)
Photos de Chantal Billard
Pyramimonas
SEM of the flagellated prasinophyte Pyramimonas gelidicola
Image: Sandy Melloy Moestrup et Walne J. Cell Sci. 36, 437-459 0979)
Prasinophyceae : Pyramimonas
Lepidodinium chlorophorum
Gould et al., 2008
Desmoconts
(Prorocentrales) D ’après Lee, 1989
Epitheca
Epicone
Hypotheca, hypocone
Dinoconts
No theca
(or thin)
Cingulum
Thick theca
Cingulum
Theca
divided in 2
parts
No cigulum
2 flagella at apex Theca with elaborated
extensions
Gymnodiniales
Suessiales
Péridiniales
Gonyaulacales
Prorocentrales
Dynophysiales
• Colonies, cell wall spines and
extensions
• Ethology : nyctemeral migrations
Profil de Chl a durant un bloom de dinoflagellés
(d ’après Eppley et al. 1968)
Adaptation to planktonic life
Haptophytes
incl. coccolithophores
- 10 % of described marine phytoplankton spcecies
(380 esp.)
- Major role in biogeochemical cycles (C, du S)
- Nanoplankton (picoplankton)
Chrysochromulina Coccolithus Hymenomonas
Emiliania huxleyi
http://microscope.mbl.edu/baypaul/microscope/general
/page_01.htm
Organic scales with/without calcification
Organic microfibrillous scales
Chrysochromulina / Prymnesium
•Proximal face : radially organised,
sectors
•Distal face : variable, may include
projections
•May serve as a matrix for
biomineralisation (coccolithophores)
Phaeocystis
Cosmopolitan
Harmful blooms (North Sea)
Références : Plankton@net, EOL, Lee (2008)
2 µm
2 µm
0,2 µm
Zingone et al. 2011) – Phaeocystis antarctica
Coccoliths
Intact Coccolith
Dissolved coccolith
Scale « matrix »
1/ Hétérococcoliths
Radial arrangment of
calcite cristals in
intracellular vacuoles
2/ Holococcolithes
Extracellular
precipitation of small
hexahedric CaCO3
cristals
• Organic scales may be
used as a matrix for
biomineralisation
• 2 major types
Emiliania huxleyi
2n
Coccoliths
n
Organic scales
Image: Remote Sensing Data Analysis Service (RSDAS)
www.npm.ac.uk/rsdas/ of the Plymouth Marine Laboratory (PML)
The haptonema• Variable size
• 3 concentric membranes, 7 microtubules
• Mouvment and capture of preys
Chrysochromulina
Lee (2008)
Caractères cytologiques et ultrastructuraux
(1) ou 2 plastes bruns jaunes
Enveloppe à 4 membranes, thylacoïdes
groupés par 3
Chl a, c, diadinoxanthine, fucoxanthine,
19 ’-hexonoyloxyfucoxanthine
Réserve principales :
glucane beta1-3 ramifié en beta 1-6
1 Haptonème (6 à 7
microtubules)
2 flagelles égaux lisses
(Prymnesiophyceae), inégaux chez
les Pavlovophyceae
Couverture Phycologia Mai 2003
Ecailles fibrillaires avec CaCO3
(coccolithes) pour certains
taxons
(Ecailles en
forme de
clous)
Calciopagus rigidus (Mediterranée)
Plankton@net
Acanthoica quattrospina
Papposphaera lepida
Discosphaera tubifera
Vargas et al. 2007
Diatomées
Dinoflagellés
Mandala de Margalef
Main functionnal groups : Silicifiers, calcifiers, + dinoflagellates
The fossil record
Dinoflagellates
Coccolithophorids
Diatoms
400500 300 200 100 0 My B.P.
Paleozoic Tr J K Ceno
Acritarchs
Pann
otia
rif
ting
Pang
ea
rift
ing
Intermittently anoxic deep ocean Deep oxic ocean
Sea level
Calcite seas Aragonite seas Calcite seas
+200m
0
-100m
150
species
100
species
500
“species”
50
“genera”
cysts of dinoflagellateAncestors?
Prasinophyte cystsPrasinophyte cysts
After Katz et al. 2006
Diapositive : W. Kooistra
Phytoplankton « Flagellates »
• Less studied,
• Pico- and nanoplankton
• Biomass and production important
(outside bloom periods of dinos, diatoms,
coccolithophores)
Plantae
Excavates
Eukaryotes consensus
phylogeny
Bauldauf 2008
Unikonts
Habrobia
SAR
(Marine
microalgae)
140 sp.
Few genera
(Dunaliella, Chlorella)
Green algae in marine phytoplankton
CHLOROPHYTA : ~ 3500 species (marine and freshwater)
« Prasinophytes »
Chlorodendrophyceae
Mamiellophyceae
« Prasinophytes »• No unique derived character
• Green platids chl a and b(2 mbs)
• Starch in plastids
• Scales / theca
• Parallell basal body
• 9 clades (classes or classes to bedescribed)
Scales « roues de
bicyclettes »
(Mamiellophyceae)
Other scale
types
Tetraselmis (Chlorodendrophyceae)
communs dans le phytoplancton marin
Common genera
Halosphaera (Pyramimonadales)
2 µm
Micromonas
Micromonas, Ostreococcus (Cl. Mamiellophyceae)
Widespread in marine picoplankton
Ostreococcus
Plusieurs génomes séquencés
0,5 µm
Cliché Web
Paulinella chromatophora
Chlorarachnion reptans
Geitler (1930) Bigelowiellabenthic or
picoplanctonic
Lund
&
Lund
(1995)
Chlorarachniophyceae (« green spider web »),
~10 marine species
Diapositive de B. de Reviers, modifiée
Lotharella “amoebiformis” strain
HajimeAmoeboid cells
Lotharella oceanica
Ota et al., 2009.
Envelopp 4 membranes
Thylacoïds by 3 (lamelles)
Nucleomorph
Chl. a + b
Chrysolaminarine (glucane b 1,3)
Mitochondrie with tubilar cristae
Ochrophyta = (~16 classes – golden-brown algae)
« Chrysomerophyceae »
Phaeothamniophyceae?
Chrysophyceae
(incl. Synurales)
Synchromophyceae
Eustigmatophyceae
Phaeophyceae
Schizocladiophyceae
Xanthophyceae
Raphidophyceae
Pinguiophyceae
Dichtyochophyceae
Pelagophyceae
Parmales -
Bolidophyceae
Bacillarriophyceae -
Diatomophyceaee
Picophagus
Aurearenophyceaea
Flagellates within phylum Ochrophyta
• Chl a and c
• Golden brown
plastid
• mbs
• 2 unequal flagella
• Mastigonems
Silicoflagellates – Dictyochophyceae
•
• Tentacules or « rhizopodes » on
amoeboid cells
• scales, spines or siliceous
squeleton
Genus Dictyocha : Constant in
coastal water
Plankton*Net Data Provider at the
Alfred Wegener Insitute for Polar and Marine Research
Lee (2008)
Chap 12 - video
Raphidophyceae
- 50 – 100 µm
- Numerous chloroplasts
-Mucocysts
-Verrucous Cells
- May be toxic
Ex : Chatonella, Heterosigma,
Bolidophyceae (parmales)
Class described in1999
Pelagophyceae
Class described in 1995
Poils
Amidon
PLASTID
•Chl a, c2
•Phycoerythrin or phycocyanin in
thylacoïds
•Envelopp 4 membranes
•Thylacoïds grouped by 2
•Nucléomorph
•Asymetric cells
•2 flagella almost equal, lateral
insersion stiff
•1 or 2 plastids yellow, red or
greeen/blue
•Vestibule with rows of ejectosomes
Cell wall = Pellicule
1 or several plaques on and under
plasmalema (sandwich)
Storage
Starch in periplastidial compartment
Cryptophyta
Env. à
4 mb
Plaques
de la
pellicule
Plantae
Excavates
Eukaryotes consensus
phylogeny
Bauldauf 2008
Unikonts
Habrobia
SAR
60°S 30°S 0° 30°N 60°N
Le Quéré et al. (2005) Global change Biology
Surf
ace C
hl a (
mgC
hl m
-3)
Classes de taille (analyse des
pigments marqueurs et de la
couleur de l’océan)
«Flagellates » in phytoplankton
• Belong to pico- and nanoplankton
• Reservoir of unknown biodiversity
• Morphological convergences : small size
• Adaptations less studied than for
microplankton
Conclusions – present research
fields
• Biodiversity description (incultivables, cryptic)
• Mecanisms of evolution (macro- and
microevolution)
• Control of blooms, successions
• Impact of abiotic environment (turbulence,
nutrients, llight) and feed-backs
• Biotic controls
Adam Steiner, Le
Jardin des sculptures,
1987, patio 45-56.
The Kingdom Protista: The Dazzling World of Living Cells
List of Chapters
• Chapter 1 INTRODUCTION
• Chapter 2 Choanoflagellates
• Chapter 3 Diplomonads
• Chapter 4 Parabasilids
• Chapter 5 Cellular Slime Molds
• Chapter 6 Acellular Slime Molds
• Chapter 7 Amoebae: Rhizopods
• Chapter 8 Amoebae: Actinopods
• Chapter 9 Chlorarachniophytes
• Chapter 10 Cryptomonads
• Chapter 11 Raphidophytes
• Chapter 12 Silicoflagellates
• Chapter 13 Pedinellids
• Chapter 14 Pelagomonads
• Chapter 15 Chrysophytes
Chapter 16 Synurophytes
Chapter 17 Diatoms
Chapter 18 Brown algae
Chapter 19 Oomycetes
Chapter 20 Xanthophytes
Chapter 21 Prymnesiophytes (Haptophytes)
Chapter 22 Dinoflagellates
Chapter 23 Apicomplexans
Chapter 24 Ciliates
Chapter 25 Euglenids
Chapter 26 Kinetoplasts
Chapter 27 Glaucophytes
Chapter 28 Red algae
Chapter 29 Green Algae: Prasinophytes
Chapter 30 Green Algae: Siphonous Groups
Chapter 31 Green Algae: Chlorophytes
Chapter 32 Green Algae: Charophytes
Chapter 33 Protists and the Origin of GreenLand Plants
Chapter 34 CREDITS
-Localise the different groups in
the consensus phylogenetic treee
provided
-Fill out the table with the main
cytological, biochemical,
ultrastructural characters of the
different groups
-Search ecologically important
representatives of each of the
groups in the litterature
