PhD position: Red Algal Life Cycle: Plasticity and Resilience in a Changing Climate - M/F

Job Description

Thesis Subject

Red algae are among the earliest multicellular eukaryotes and play fundamental ecological and economic roles in coastal ecosystems. Species such as Gracilaria chilensis contribute to habitat formation, support biodiversity, and are widely exploited for phycocolloids and other bioactive compounds. A defining feature of red algae is their complex three-phasic life cycle, which strongly shapes population dynamics, dispersal capacity, and resilience to environmental change.
However, natural populations frequently display non-canonical reproductive phenotypes, including
asexual reproduction (apospory, apogamy) and individuals bearing mixed reproductive structures from different life-cycle stages on the same thallus. The drivers, regulation, and ecological consequences of these mixedphase phenotypes remain largely unknown, representing a major gap in our understanding of red algal biology.
These phenotypes may reflect adaptive reproductive plasticity in response to environmental variability, or disruptions in life-cycle regulatory networks. Resolving this question is essential for predicting how red algal populations will respond to climate change and for improving conservation and aquaculture strategies. Using Gracilaria chilensis as a model system, this project aims to uncover the genetic, physiological, and environmental mechanisms controlling life-cycle transitions. We will combine genomics, transcriptomics, physiology, and metabolic network modeling to identify the processes underlying reproductive variation.
The project is inherently interdisciplinary, as the regulation of life-cycle transitions spans multiple biological scales. Molecular analyses will identify candidate regulatory mechanisms, while physiological measurements will assess their functional consequences at the organismal level. These datasets will be integrated into metabolic network models to provide a systems-level understanding of how environmental factors influence reproductive strategies. By integrating environmental variation, gene regulation, and reproductive strategies, this project will advance our understanding of evolution and provide a predictive framework for the response of red seaweeds with aquaculture applications to global change.

The main objectives of the project are:
(1) identify genes and regulatory pathways associated with life-cycle transitions using genomic and transcriptomic approaches;
(2) characterize physiological differences between canonical and mixed-phase individuals;
(3) determine whether shifts in reproductive phenotype are associated with changes in metabolic network organization.

Your Work Environment

The successful applicant will be attached to the 515 Doctoral School ( École doctorale Complexité du vivant) of the Sorbonne University in Paris. The project will be performed at the UMR 8227 Integrative Biology of Marine Models at the Station Biologique de Roscoff (http://www.sb-roscoff.fr/about-roscoff-marine-station/missions.html). The host institute is a centre of marine biology and oceanographic research situated in the town of Roscoff on the north coast of Brittany (France) about 60 km east of Brest. The SBR has about 200 permanent employees.
The PhD project is funded by CNRS 'La Mission pour les initiatives transverses et interdisciplinaires (MITI)' programme and will be realized in strong collaboration with Pontifical Catholic University of Chile (UC Chile) and Universidad Austral de Chile (UACh).
The supervision of the doctorate is provided in co-direction by Agnieszka Lipinska (Algal Genetics group, Station Biologique de Roscoff), Sylvain Faugeron (Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile) and Marie-Laure Guillemin (Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile).

Constraints and risks

No specific constraints or risks.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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