Download Mention Ecologie, Biodiversité et Evolution

Proposal of Master 2 thesis October 2016
Kelpadapt
Environmental changes, gene flow and local adaptation in kelps
Hosting laboratory:
UMI3614 Evolutionary Biology and Ecology of Algae
Station Biologique de Roscoff, Place George Tessier, Roscoff, France
Supervisors :
Name Myriam Valero (co-supervision with the Post-Doc : Bertrand Jacquemin)
Tel : 0298292328
Email : [email protected]
[email protected]
References :
Araújo, R. M., J. Assis, R. Aguillar, L. Airoldi, I. Bárbara, I. Bartsch, T. Bekkby, H. Christie, D. Davoult, S. Derrien-Courtel, C.
Fernandez, S. Fredriksen, F. Gevaert, H. Gundersen, A. Le Gal, L. Lévêque, N. Mieszkowska, K. M. Norderhaug, P.
Oliveira, A. Puente, J. M. Rico, E. Rinde, H. Schubert, E. M. Strain, M. Valero, F. Viard, and I. Sousa-Pinto. 2016.
Status, trends and drivers of kelp forests in Europe: an expert assessment. Biodiversity and Conservation:1-30.
Assis, J., N. C. Coelho, T. Lamy, M. Valero, F. Alberto, and E. Á. Serrao. 2015. Deep reefs are climatic refugia for genetic
diversity of marine forests. Journal of Biogeography.
Billot, C., C. R. Engel, S. Rousvoal, B. Kloareg, and M. Valero. 2003. Current patterns, habitat discontinuities and population
genetic structure: the case of the kelp Laminaria digitata in the English Channel. Marine Ecological Progress Series
253:111-121.
Couceiro, L., M. Robuchon, C. Destombe, and M. Valero. 2013. Management and conservation of the kelp species Laminaria
digitata: using genetic tools to explore the potential exporting role of the MPA "Parc naturel marin d'Iroise".
Aquatic Living Resources 26:197-205.
Oppliger, L. V., P. von Dassow, S. Bouchemousse, M. Robuchon, M. Valero, J. A. Correa, S. Mauger, and C. Destombe. 2014.
Alteration of Sexual Reproduction and Genetic Diversity in the Kelp Species Laminaria digitata at the Southern
Limit of Its Range. PLoS One 9:e102518.
Pereira, T. R., A. H. Engelen, G. A. Pearson, M. Valero, and E. A. Serrão. 2015. Contrasting timing of life stages across
latitudes – a case study of a marine forest-forming species. European jouranl of Phycology 50:361-369.
Pante, E., N. Puillandre, A. Viricel, S. Arnaud-Haond, D. Aurelle, M. Castelin, A. Chenuil, C. Destombe, D. Forcioli, M. Valero,
F. Viard, and S. Samadi. 2015. Species are hypotheses: avoid connectivity assessments based on pillars of sand.
Molecular Ecology 24:525-544.
Raybaud, V., G. Beaugrand, E. Goberville, G. Delebecq, C. Destombe, M. Valero, D. Davoult, P. Morin, and F. Gevaert. 2013.
Decline in Kelp in West Europe and Climate. PLoS One 8:e66044.
Robuchon, M., L. Le Gall, S. Mauger, and M. Valero. 2014. Contrasting genetic diversity patterns in two sister kelp species
co-distributed along the coast of Brittany, France. Molecular Ecology 23:2669-2685.
Valero, M., C. Destombe, S. Mauger, C. Ribout, C. R. Engel, C. Daguin-Thiebaut, and F. Tellier. 2011. Using genetic tools for
sustainable management of kelps: a literature review and the example of Laminaria digitata. Cahiers de Biologie
Marine 52:467-483.
Description of the Master project
The limits of habitats a species can occupy are generally difficult to predict, or even to characterize. This
is particularly true for species with a wide distribution range, often accompanied by a range of habitats to
which the species is acclimated or locally adapted. One critical aspect of local adaptation is the balance
between neutral (i.e. genetic drift and gene flow) and selective forces that shape the dynamics of the genetic
diversity, and ultimately the outcome of this evolutionary process. To understand how species evolve in their
range, local adaptation needs to be investigated by jointly estimating adaptive divergence, gene flow and
restrictions to effective dispersal, and genetic drift. The balance between these evolutionary forces is poorly
studied in marine taxa, specifically in marine algae.
Kelps are key components of cold to temperate coastal ecosystem worldwide. Several studies (including
those of the sponsoring team) showed that these marine forests are currently under serious threats and
notable shifts of their distribution ranges (Raybaud et al. 2013 ; Assis et al. 2015 ; Araújo et al. 2016).The aim of
this Master thesis is to significantly increase our understanding of how environmental changes will affect the
spatial and temporal distribution of genetic diversity and the processes of local adaptation.
To fulfil this objective, population genetics approaches will be combined with crosses between
individuals coming from different habitats (1) to estimate the level of connectivity between populations located
in different habitats and (2) to study the interaction between dispersal and reproductive barriers due to habitat
divergence. In addition, in order to assess the level of genetic drift, effective population size will be estimated
from a temporal sampling of genetic diversity.
This study will be carried out on the kelp Laminaria digitata. Genetic markers (12 microsatellite locus,
Robuchon et al. 2014) necessary for the study of population genetics structure are routinely used the
laboratory. We have also a good knowledge of the crossing methodology (Oppliger et al. 2014). Finally,
populations of this species are studied since 1997 (Billot et al. 2003 ; Couceiro et al. 2013)) and we have a very
good collection of populations sampled at different dates (Valero et al 2011). The student will benefit from
technical assistance for the training methods of genotyping and breeding.
Calendar :
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January-February : sampling individuals (8 populations) and implementation of the breeding experiment
(30 crossings), literature review on the subject.
February-March : genotyping individuals from the spatio-temporal sampling (300 individuals)
April May : Analysis of breeding experiment and genetic structure
May-June : writting of the report
This Master 2 project is proposed as part of the European project MARFOR: Variability and Functional Dynamics
of Responses of Marine Forests to Global Change (BiodivERsA3-2015-165) involving 8 partners. By combining
approaches of physiology, ecology and population genetics, the objective of MARFOR is to understand the
geographical variation in biodiversity of several large brown algae (Laminaria and fucales) that affect fitness
and consequently the future trajectories and fate of these keystone ecosystems. This Master could be
continued as a PHD project. Funding is already partially achieved (half scholarship funded by MARFOR). A cofinancing application will be made in 2017 and the PHD subject will be submitted to the French doctoral school
227 MNHN / UPMC (http://www.mnhn.fr/fr/enseignement-formation/enseignement-superieur/ecoledoctorale). This project will be carried out at the Roscoff Biological Station in the UMI3614 (http://www.sbroscoff.fr/fr/umi-biologie-evolutive-et-ecologie-des-algues), an international joint laboratory Franco-Chilean .
The results to be obtained in this project will be compared to those that are currently developed with similar
approaches by Chilean researchers of the lab also participating to MarFOR project.