Untitled - Station Biologique de Roscoff

ème
7 Journée des Jeunes
Chercheurs de la station
biologique de Roscoff
Ma thèse en 180 secondes
Résumés – Abstracts
Secondary sexual characters and hybridization in two species of the Jaera
albifrons complex
Ambre RIBARDIERE 1
1
University Pierre and Marie Curie, Station Biologique de Roscoff, France
Enzymatic hydrolysis of algal polysaccharides to produce active
cosmetic ingredients
LE SOURD F1., CUEFF M.1, BOYEN C.1, JAM M. 1, POTIN P. 1, CZJZEK M. 1
1
CNRS, Université Pierre et Marie Curie Paris-06, UMR 8227 Laboratoire de Biologie Intégrative
des Modèles Marins, Station Biologique de Roscoff, CS90074, F-29688 Roscoff cedex, France
KEYWORDS: ALGAE, POLYSACCHARIDES, COSMETICS
Every day numerous researchers are working on algae. Some people may wonder to what kind of
application this could lead. This presentation will provide an example of an application that this research field
could offer. Thanks to years of algal carbohydrate research in Roscoff, the Oligomar-skin project was created
connecting the Station Biologique de Roscoff to the company called Lessonia, located in Brittany. Lessonia is
currently selling ingredients for cosmetics and the aim is to develop a new active ingredient for their product
line, based on local natural resources. Today, polysaccharides as alginates or carrageenans are extracted for their
rheological properties, as gelling or thickening, in food industries. In this project, these are the raw materials for
cosmetic applications. Indeed, carrageenans and porphyrans are extracted from cell wall of red algae. Then, by
using specific marine bacterial enzymes, which are produced and purified, we can hydrolyze the polysaccharide
to get smaller molecules of different sizes. Preliminary tests on these oligosaccharides showed promising results
because they induce an immune-stimulating activity and thus especially could have an impact on skin cells.
Effect of the thermal instability/stability of the environment on the
evolutive pentencial and the adaptive strategy of the marine invertebrates.
BIOY ALEXIS
The ABICE Team. UMR 7144 CNRS-UPMC, Station Biologique de Roscoff, Place Georges Teissier, 29680
Roscoff FRANCE
KEYWORDS: SELECTION ; TEMPERATURE ; ANNELIDS
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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Location and roles of cell-wall polysaccharides during early development in
the brown algae Ectocarpus and Fucus
Amandine SIMEON1,2, Cecile HERVE 1,2 and Bernard KLOAREG 1,2
1
Sorbonne Universités, UPMC Univ Paris 06, UMR 8227, Integrative Biology of Marine Models
Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, Brittany, France
2
CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688,
Roscoff cedex, Brittany, France
KEYWORDS: BROWN ALGA, CELL-WALL AND DEVELOPMENT
Brown algae are evolutionary distant from land plants and animals. Multicellularity is closely dependent
on the development of an extracellular matrix or cell wall (Popper and al., 2011). In the brown algal model
organisms Fucus and Ectocarpus, several studies suggest a crucial role of the cell wall in early development
(Berger and al., 1994; Bail and al., 2011). In brown algae, the cell-wall is essentially composed of three main
polysaccharides: cellulose, alginates and sulfated fucans. However, all the data available so far derived from
chemical extractions on the entire algae. Specific tools all missing to locate precisely the cell-wall
polysaccharides in-situ. In land plants, immunohistochimical methods based on specific monoclonal antibodies
have been largely used. We have now developed specific probes against sulfated fucans (Torode and al. 2015)
and alginates. This allows to gain a better view of the polysaccharide localisation in context. These results set the
bases for studying the role of the cell wall polysaccharides during development of Fucus and Ectocarpus.
Preliminary results show that a correct cell wall deposition is crucial to cell elongation and early development in
both models.
REFERENCES
Le Bail, A., Billoud, B., Le Panse, S., Chenivesse, S., and Charrier, B., 2011. ETOILE Regulates Developmental Patterning
in the Filamentous Brown Alga Ectocarpus Siliculosus. The Plant Cell 23 (4): 1666-78.
Berger, F., Taylor, A., and Brownlee C., 1994. Cell Fate Determination by the Cell Wall in Early Fucus Development ».
Science 263 (5152): 1421-23.
Popper, Z.A., Michel, G., Hervé, C., Domozych, D., Willats, W., Tuohy, M., Kloareg, B., and Stengel, D., 2011. Evolution
and Diversity of Plant Cell Walls: From Algae to Flowering Plants. Annual Review of Plant Biology 62 (1): 567-90.
Torode, T, Marcus, S., Jam, M., Tonon, T., Blackburn, R., Hervé, C., and Knox, J.P. 2015. Monoclonal Antibodies Directed
to Fucoidan Preparations from Brown Algae . PloS One
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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Barriers to gene flow between sympatric species genus Ciona
MALFANT MARINE
Station biologique de Roscoff, France
KEYWORDS: MARINE ECOLOGY, BARRIERS, EXPERIMENTATIONS
Barriers to gene flown, an experimental ecology approach.
Control of blooms and successions of diatoms in the Western English
Channel by biotic interactions.
Laure ARSENIEFF
Station Biologique de Roscoff – CNRS/UPMC, France
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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Study of a polymicrobial disease in the Pacific oyster Crassostrea gigas
Adèle JAMES 12, Frédérique LE ROUX 12, Yannick LABREUCHE 12
1
2
IFREMER Unité de physiologie fonctionnelle des organisms marins, France
Station biologique de Roscoff Laboratoire de biologie intégrative des modèles marins, France
KEYWORDS: VIBRIO - INTERACTIONS - VIRULENCE
Vibrio have been associated with recurrent mortality events of Pacific oysters in France, resulting in
losses of up to 100% of the production. We observed that during oyster mortality events in an oyster farming
area particular ecological populations of Vibrio are more abundant in oyster tissue than in surrounding seawater
(Bruto, et al. unpublished data). Here we define an ecological population as the genetic unit representing a
cohesive ecology, gene flow and social attributes (Hunt et al., 2008). We also showed that some ecological
populations contain a high proportion of pathogenic strains, while others only contain non-virulent isolates.
Interestingly, experimental infection data suggest that disease onset can be facilitated by the presence of such cooccurring non-virulent strains (Lemire et al., 2014). The aim of my PhD is to investigate this poly-microbial
oyster disease by investigating i) the molecular mechanisms involved in oyster infection by each
ecological/virulent population; ii) the molecular basis of interaction between populations during the disease.
REFERENCES
Hunt DE, David LA, Gevers D, Preheim SP, Alm EJ, Polz MF., 2008. Resource partitioning and sympatric differentiation
among closely related bacterioplankton, Science.
Lemire A, Goudenège D, Versigny T, Petton B, Calteau A, Labreuche Y, Le Roux F 2014. Populations, not clones, are the
unit of Vibrio pathogenesis in naturally infected oysters. ISME Journal.
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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From Chondrus to Columbus: how to use your PhD out of the lab
Nathalie KOWALCZYK 1,2, Catherine BOYEN 2
1
University Pierre and Marie Curie - Paris 6, France
2
CNRS - Station Biologique de Roscoff, France
KEYWORDS: ALGAE, KNOWLEDGE TRANSFER, MARINE BIOLOGICAL RESOURCES
This presentation aims to give you an example of what you can do with a PhD, without necessarily
doing a Postdoc.
My scientific journey started with an internship on the morphogenesis of the brown alga Ectocarpus
siliculosus [Le Bail, 2010], followed by a thesis on the red alga Chondrus crispus where I studied genomics
[Collén, 2013], stress and photosynthesis [Kowalczyk, 2013]. During these four years, I explored the marine
world, and how much there is still to unravel.
Then, I needed to see science from a new perspective. I enrolled into a new adventure, diving into the
arcane of what is beyond us: management! I am now part of the COLUMBUS project, funded by the EU
program Horizon2020, which aims to ensure that knowledge generated by marine and maritime research is
visible and efficiently transferred to potential users: other researchers, but also industry, policy makers and
citizens. With the help of Catherine Boyen, I’m in charge of assessing and transferring the knowledge related to
Marine Biological Resources, from European and national projects.
If this is a story of how to make an unusual use of your PhD, it is also a way to show that science is
not just about publishing.
REFERENCES
A Le Bail, B Billoud, N Kowalczyk, M Kowalczyk, M Gicquel, S Le Panse, S Stewart, D Scornet, JM Cock, K Ljung & B
Charrier (2010) "Auxin metabolism and function in the multicellular brown alga Ectocarpus siliculosus" Plant Physiology
153:128-44.
N Kowalczyk, F Rappaport, J Collén, C Boyen, WA Wollman & P Joliot (2013) "Photosynthesis in Chondrus crispus: the
contribution of energy spill-over in the regulation of excitonic flux." Biophysica et Biochemica acta 1827: 834-42.
J Collén, B Porcel, W Carré, ..., N Kowalczyk, ... & C Boyen (2013) "Genome structure and metabolic features in the red
seaweed Chondrus crispus shed light on evolution of the Archaeplastida" PNAS 110: 5247-52.
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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Effects of recent climate warming on the distribution of subtidal benthic
macrofauna in the English Channel
François GAUDIN 1,2, Eric THIEBAUT 1, Nicolas DESROY 2
1
Sorbonne Universités, UPMC Univ Paris 6, CNRS, Station Biologique de Roscoff, UMR 7144 Adaptation et
Diversité en Milieu Marin, Place Georges Teissier, CS 90074, 29688 Roscoff cedex, France
2
IFREMER, Laboratoire Environnement & Ressources Bretagne Nord, CRESCO, 38 rue du Port Blanc, BP
70134, 35801 Dinard cedex, France
KEYWORDS: CLIMATE CHANGE, MACROFAUNA, ENGLISH CHANNEL
In the North-East Atlantic, the English Channel constitutes a biogeographical transition zone between
the cold-temperate Boreal province in the North and the warm-temperate Lusitanian province in the South.
Historical works carried out from the late 1950’s to the 1970’s have shown that the distribution of macrobenthic
invertebrates in the Channel was influenced by edaphism and thermal gradients from West to East so that many
species were here in their southern or northern range limits. In parallel, long-term environmental physical data
highlighted an increase in the sea temperature during the last 30 years and a thermal regime shift in the NorthWest Europe since the 1980’s.
The aims of my PhD are (1) to assess changes in the spatial distribution of subtidal macrobenthos
regarding climate change by comparing historical data and present data and (2) to develop predictive habitat
models for a selection of species based on historical data to test their relevance in predicting the response of
coastal marine species to climate change. This will be achieved in relation to the first aim with the use of data
recently sampled at 254 stations distributed along three transects from the Ushant Sea to the central Channel.
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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From environmental distribution to mechanisms of adaptation in the
planktonic picocyanobacterial genus Synechococcus
Hugo DORÉ 1
1
University Pierre and Marie Curie), UMR 7144 Adaptation and Diversity in Marine Environments, Marine
Phototrophic Procaryotes (MaPP) Team, Station Biologique de Roscoff, France;
KEYWORDS: PHYTOPLANKTON, ADAPTATION, ENVIRONMENTAL NICHE
Phytoplankton, through oxygenic photosynthesis, is a major player of surface oceans both as primary
producer in complex trophic networks and as a massive carbon fixer. Being part of marine phytoplankton,
Synechococcus is one of the most abundant photosynthetic organisms on earth. We describe here the global
distribution of members of this highly diverse group, and propose future investigations to understand the
mechanisms of adaptation to environmental conditions.
Detection of cell-wall polysaccharides in brown algae
Delphine DUFFIEUX 1,2, Cécile HERVÉ 1,2
1
Sorbonne Universités, UPMC Université Paris 06, UMR 8227, Integrative Biology of Marine Models, Station
Biologique de Roscoff, CS 90074, 29688 Roscoff CEDEX, France
2
CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688
Roscoff CEDEX, France
KEYWORDS: CELL-WALL IMMUNOCYTOCHEMISTRY, IMMUNOFLUORESCENCE MICROSCOPY, ALGAL CELLWALLS
Brown algae share with plants the property of having cells surrounded by a polysaccharides-rich cellwall. However, and due to their phylogenetic distances, the majority of their components are different. Unique
methods in microscopy have been previously developed to detect and map polysaccharides in the cell-wall from
land plants [Hervé et al, 2011]. A part of my project is to adapt these plant-based detection techniques to our
brown algal models. They are based on specific staining and immunohistochemical techniques. The targeted
polymers are the cellulose fibers, hemicelluloses, sulfated polysaccharide and alginates.
REFERENCE
Hervé C, Marcus SE, Knox JP (2011). Monoclonal antibodies, carbohydrate-binding modules and the detection of
polysaccharides in plant cell walls. In: The Plant Cell Wall: Methods and Protocols. Ed. Popper ZA. Methods in
Molecular Biology, New York: Springer Sci./ Bus. Media, 715, p103-13.
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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“Genetic and cellular characterization of gamete parthenogenesis in brown
alga Ectocarpus”
Laure MIGNEROT
Supervisors : Susana Coelho, Mark Cock
UMR 8227 CNRS-UPMC, Integrative Biology of Marine Models Laboratory, Algal Genetics Group,
Station Biologique, Place Georges Tessier, 29680 ROSCOFF, France
KEYWORDS: ASEXUAL REPRODUCTION, BROWN ALGAE, SEX LOCUS
In the last decades, Ectocarpus, a small alga from the Stramenopile’s group, has been used as a model
for brown algae. Current research projects in the Algal Genetics Group are aimed at understanding the
reproductive biology of this filamentous alga, its life cycle and how developmental processes work. The life
cycle of Ectocarpus can be sexual or asexual, via parthenogenesis. Parthenogenesis occurs when a gamete
develops into a new individual without fusion with a gamete from the opposite sex. It is a process that is very
rare in mammals and that can be found in numerous plants and some insects. Parthenogenesis has been analyzed
in a population of Ectocarpus siliculosus from Naples, where usually only female gametes can make the
parthenogenesis. This results lead us to believe that there could be a genetic link between parthenogenesis and
the sex locus.
My PhD project is to investigate the genetic and cellular basis of gamete parthenogenesis in Ectocarpus
using approaches to fine map the parthenogenesis locus, and to investigate the function and the phenotypic effect
of this locus in gametes.
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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PKS III Project: Overview of an innovative project in marine
biotechnologies
Agnès MORIN 1,2, Ludovic DELAGE 2, Pierre-Antoine CHARIER1, Hervé LE DEIT1, Philippe POTIN2,
Laurence MESLET-CLADIERE3, Catherine LE BLANC2
1
SATT Ouest Valorisation SAS, France
Station Biologique de Roscoff – CNRS/UPMC, France
3
Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, France
2
KEYWORDS: ENZYME PRODUCTION – SCALE UP – BIOTECHNOLOGIES
Phlorotannins are a wide family of secondary metabolites in brown algae. Among their numerous
functions, phlorotannins might serve as a chemical defense against grazing and provide protection against UV
radiation. Phlorotannins all derive from the polymerization of a simple block molecule, phloroglucinol (1,3,5trihydroxybenzene). The formation of this compound constitutes the first step of the biosynthetic pathway for
phlorotannins [Meslet-Cladiere et al. 2013]. Phloroglucinol is also used at an industrial level, alone, or as a
starter for longer chemical reactions; however, its synthesis involves hazardous reagents and steps [Achkar et al.
2005]. Recently, a type III Polyketide Synthase (PKS) from Ectocarpus siliculosus, EsiPKS1, was discovered,
which is involved in the catalytic synthesis of phloroglucinol. This has led to the possibility of producing this
interesting compound using marine biotechnologies.
The “PKS III” project is financed and carried out by SATT Ouest Valorisation. It offers to give proof
of concept concerning the development of an innovative and safer production process for phloroglucinol using a
patented algal enzyme, EsiPKS1 [Delage et al. 2014]. An optimization of batch fermentation conditions has
been conducted in order to improve enzyme production yields and perform a first scale-up step. Phloroglucinol
production, extraction and quantification experiments are currently in progress, with the goal of scaling up the
production process for industrial purposes.
REFERENCES
Achkar, Jihane, Mo Xian, Huimin Zhao, and J. W. Frost. 2005. “Biosynthesis of Phloroglucinol.” Journal of the
American Chemical Society 127 (15): 5332–33. doi:10.1021/ja042340g.
Delage, L., L Meslet-Cladière, P. Potin, and S. Goulitquer. 2014. Use of recombinant Type III Polyketide
Synthases of marine brown algae. United States Patent Application Publication US2014/0315269A1,
issued
October
2014.
https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US20140315269.pdf.
Meslet-Cladiere, L., L. Delage, C. J.- J. Leroux, S. Goulitquer, C. Leblanc, E. Creis, E. A. Gall, V. StigerPouvreau, M. Czjzek, and P. Potin. 2013. “Structure/Function Analysis of a Type III Polyketide Synthase in the
Brown Alga Ectocarpus siliculosus Reveals a Biochemical Pathway in Phlorotannin Monomer Biosynthesis.”
The Plant Cell 25 (8): 3089–3103. doi:10.1105/tpc.113.111336.
7éme Journée des Jeunes Chercheurs de la Station Biologique de Roscoff – 3 décembre 2015 – Résumés « MT180 »
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