Recombination DNA Technology (Nucleic Acid Hybridization )
Global ocean’s protist metabarcoding
1. Global ocean’s protist
metabarcoding
Colomban de Vargas, Stéphane Audic, Nicolas Henry,
Johan Decelle, Frédéric Mahé, Cédric Berney,
Sébastien Colin, Sarah Romac, Daniel Richter, Ian
Probert, Raffaele Siano, Gipsi Lima-Mendez, Jeroen
Raes, Chris Bowler, Patrick Wincker, Eric Karsenti, &
the Tara Oceans Consortium.
2.
3.
4.
5. 43 samples (viral fraction <0.22um) from 26 stations; 2.16 billion
Illumina reads (200X larger than the Pacific Ocean Virome).
pelagic upper-ocean viral community
sequence space is now well-sampled and
approaches a limit of ca. 1 million PCs
Protein Clusters
(ORFs)
6. • 68 stations68 stations 7.2 Tbp DNA data7.2 Tbp DNA data
• 3 depths3 depths in the context ofin the context of
• 243 samples243 samples the environmentthe environment
A genetic inventory of the ocean:A genetic inventory of the ocean:
Ocean Microbial Reference Gene CatalogOcean Microbial Reference Gene Catalog
High sequencing coverageHigh sequencing coverage
• only few new genes per
additional sample
• 4 x more genes than in
human gut microbiome
7.
8. meta-barcoding – V9 rDNA, the microscope of the III millenary
334 plankton communities
4 organismal size fractions
47 stations,sub-surface + DCM layers (photic zone)
~ 2 millions genetic barcodes per sample (total of ~800
million metabarcodes)
10. Reaching the boundary of total eukaryotic plankton diversity
in the world sunlit oceans (tropical to temperate):
Illumina reads # (million)
0 100 200 300 400 500
All together ‘pico-nano’ - [0.8-5 ]μm ‘nano’ - [5-20 ]μm ‘micro’ - [20-180 ]μm ‘meso’ - [180-2,000 ]μm
OTU #
30,000
60,000
90,000
0
‘pico-nano’ ‘nano’ ‘micro’ ‘meso’
OTUdiversity-Shannon
1
2
3
4
5
6
1.2./100,000
1.3/10,000
7.7/100,000
1.1/10,000
8.0/100,000
Organismal size
fraction(µm)
3 - 20
0.8 - inf
0.8 - 5
0.8 - 20
million reads
2,000,000
1,500,000
1,000,000
500,000
0
#ofmetabarcodes
5,000
4,000
3,000
2,000
1,000
0
ResampledOTUrichness
0.06
0.04
0.02
A
B
0.2 - 3
Slopeofrarefactoncurve
180 - 2,000
5 - 20
20 - 180
All together
million reads
‘pico-nano’ ‘nano’ ‘micro’ ‘meso’
[0.8-5µm] [5-20µm] [20-180µm] [180-2,000µm]
0 100 200 300 400 500
‘pico-nano’ ‘nano’ ‘micro’ ‘meso’ 10 2 3 4
C
Abundance(reads#)Richness(OTU#)
‘pico‐nano’ ‘nano’ ‘micro’ ‘meso’
Alv
Dinoflagellate
Metazoa
Metazoa
Metazoa (93%)
Metazoa (94%)
Metazoa (96%)
Metazoa (99.5%)
Metazoa (99.9%)
MetazoaFungi
Fungi
Fungi
Dinoflagellate Dinoflagellate
Dinoflagellate
Dinoflagellate
Dino-
flagellate
Dino-
flagellate
Dino
Others
Others
Others
Others
Others
Others
Others
MALV
MALV MALV
MALV
MALV
MALV
MALV
A lv A lv A lv
A lv
Alv
Alv
Alv
Alv - Alveolata
Amoe - Amoebozoa
Und - UndeterminedUna - Unassigned Prok - Prokaryote
Rhiz
Rhiz
Rhiz
Rhiz
Prok
Prok
Prok
Prok
Prok
Prok
R h iz
U n a
U n a
U n a U n a
Una Una
R h iz
R h iz
E x c
E x c
E x c
Exc
Rhiz
Arch - Archaeplastida
Arch
A r c h
A r c h
Arch
Rhiz - RhizariaExc - Excavata
Exc Exc
Inc - Incerta sedis
Inc
In c
Opis - Opisthokonta
Opis
Opis
O p is
O p is
O p is
O p is
Opis
Opis
Stram - Stramenopila
Stram
S t r a m
S tr a m
Stram
Stram
Stram
Stram
N = ~114 million
N = ~92,000 N = ~57,000 N = ~46,000 N = ~45,000
N = ~135 million N = ~121 million N = ~135 million
150 000 genetic types (rDNA OTUs) of eukaryotic plankton
Following a Preston curve
12. phototroph (phytoplancton)
parasite
osmotroph/saprotroph
phagotroph
✓ <1% of the OTUs are strictly identical to reference sequences.
✓ Even in known groups, genetic novelty is massive (e.g.
diatoms, dinoflagellates).
✓ ~60 branches of the tree (2/3) are basically ignored from
plankton ecology (~25% of assignable OTUs).
✓11 lineages are ‘hyper-
diversified (>1,000 OTUs);
mostly heterotrophic protists
in poorly known eukaryotic
supergroups (e.g.
diplonemids).
✓ Overall poor diversity of
phototrophic lineages
(phytoplankton), in
comparison to heterotrophic
protists)
✓ Hyper-diversification in
lineages extending across
larger size-fractions, as well
as their known parasites.
✓ >85% of eukaryotic OTUs belong to protists (zoo- not that
important)
13. A large proportion of the uncovered diversity
represents known or putative parasites / parasitoids.
examples of
lineages
infecting
diatoms
Rhynchopus coscinodiscivorus
(Diplonemida) infecting
Coscinodiscus concinnus
Cryothecomonas
longipes (Cercozoa)
feeding on
Thalassiosira rotula
plasmodium of
Phagomyxa odontellae
(Cercozoa) inside cells
of Odontella sinensis
Pirsonia diadema
(Stramenopila) infecting
Coscinodiscus wailesii
14. Dinomyces arenysensis
(Chytridiomycota) infecting
Alexandrium sp.
examples of
lineages infecting
dinoflagellates
Amoebophrya sp.
(MALV-II, Alveolata)
infecting Alexandrium sp.
zoospores of Parvilucifera sinerae
(Perkinsea, Alveolata) released
from Dinophysis caudata
15. examples of lineages
infecting metazoans
Vampyrophrya
pelagica
(Ciliophora,
Alveolata)
infecting
a copepod
Paramikrocytos canceri
(Ascetosporea, Cercozoa)
infecting Cancer pagurus
Cephaloidophoroids
(Apicomplexa, Alveolata),
parasites of copepods
Blastodinium sp.
(Dinophyceae, Alveolata)
infecting a copepod
Paradinium poucheti
(Ascetosporea, Cercozoa)
infecting Clausocalanus sp.
17. 227 tree species (out of ±16,000) account for half of all trees in Amazonia
269 OTUs:
hyperdominant & cosmopolitan 48%
of all reads
’Hyperdominance and cosmopolitasnism’
25% have poorly
defined identity
(< 95%)
11 are not
assignable
at 85%
18. If 2 species always occur together (co-occurrence)
-> mutualism, commensalism, similar niche?
If 2 species never occur together (mutual exclusion)
-> competition, amensalism, opposing niches?
127,995 associations
92,633 taxon-taxon
35,362 taxon-env
co-occurrence much
more common than
exclusion
•Data processing: sample-size
normalization, keeping proportion of
unclassified + filtered.
• 2 similarity measures: Spearman and KL
similarity
• P-value calculation by matrix
permutation (row shuffling),
renormalization and bootstrapping (Faust
et al. 2012).
•P-value merging (edges supported by >=
2 methods)
•Multiple test correction (Benjamini-
Hochberg).
Prokaryotes: miTag abundances
Phages: metagenomic contig abundances
Protists: 18S metabarcode abundances
Environmental contextual data
68 stations, 2 depths, 7 size fractions
20. Experimental validation of network-predicted interaction
(photosymbiosis)
Model for network-driven
hypothesis generation
Laser scanning confocal microscopy (LSCM) of acoel flatworm
with endosymbiotic green algae (Tetraselmis)
21.
22. UniEuk – towards a universal taxonomic framework
and integrated reference gene databases for
eukaryotic biology, ecology, and evolution
A community-based initiative, highly complementary to EukRef
24. To address the current deluge of genetic data from environmental
genetic surveys, meta-barcoding, -transcriptomics, -genomics, single-cell
transcriptomics and genomics, a common taxonomic framework is critical.
Without it, results of different studies using different genes
and different reference databases would not be comparable.
common taxonomic framework
gene 1
reference
database
gene 2
reference
database
gene 3
reference
database
gene 4
reference
database
One taxonomic framework for multiple genetic markers
25. UniEuk: a pragmatic implementation
gene reference
databases
universal
taxonomic
framework
existing
genetic data
repositories
27. UniEuk: a community-based effort
UniEuk web
portal
Redmine
environment
taxonomy
implemente
r
database
implemente
r
experts / curators
on a web protal, experts/curators have access to the
latest version of the framework and databases
experts/curators use a redmine environment to provide
feedback, flag issues, make suggestions of changes
the implementers use this feedback to improve the
framework/databases and regularly update the web
portal
28. UniEuk Steering Committee
Sina Adl, University of Saskatchewan
Guy Cochrane, EMBL-EBI
Colomban de Vargas, Station Biologique de Roscoff
Frank Oliver Glöckner, Max Planck Institute and Jakobs University
Eunsoo Kim, American Museum of Natural History
Laura Wegener-Parfrey, University of British Columbia
Pelin Yilmaz, Max Planck Institute and Jakobs University
Editor's Notes
85% of the diversity belongs to protists
1/3 is unassignahttp://taraoceans.sb-roscoff.fr/EukDiv/ble (80%)
87,000 OTUs are assignable
381 cosmopolitan OTUs represent 68% ogf reads; 269 OTUs with &gt;100,000 reads represent 48% of all reads; 25% of cosmoplolitan OTU have relatively poor identity (&lt;95%) to ref seq. 11 unknowns
Most links involve syndiniales MALV-I and MALV-II clades associated to zooplankton and, to a lesser extent, to microphytoplankton (excluding diatoms). This emphasizes the role of alveolate parasitoids as top-down effectors of zooplankton and micro- phytoplankton population structure and func- tioning (3), although the latter group is also affected by grazing (1). The meso-planktonic net- works contain known syndiniales targets (Dino- phyceae, Ciliophora, Acantharia, and Metazoa) (Fig. 3B) (56). In large size fractions, we found interactions between known parasites and groups of organisms that in theory are too small to be their hosts (57); 32% of these associations involved the abundant and diverse marine stramenopiles (MASTs) and diplonemids (other Discoba and Diplonema) (10). Ecophysiology studies (58, 59) suggest a parasitic role for these lineages. The association of these groups with other parasites would be explained by putative co-infection of the same hosts. Contrasting with the above observa- tions, we found phytoplankton silicifiers (dia- toms) displaying a variety of mutual exclusions. One possible interpretation of this is that diatom silicate exoskeletons (60) and toxic compound production (49) could act as efficient barriers against top-down pressures (61).
acoel flatworms (Symsagittifera sp.) together with their photosynthetic green microalgal endosymbionts (Tetraselmis sp.) (red)
laser scanning confocal microscopy (LSCM), three-dimensional (3D) recon- struction, and reverse molecular identification on flatworm specimens isolated from Tara Oceans preserved morphological samples. We observed mi- croalgal cells (5 to 10 mm in diameter) within each of the 15 isolated acoel specimens (Fig. 4) (66). The 18S sequence from several sorted holobionts matched the metabarcode pair identified in the co-occurrence global network.