Anne-Sophie Blervacq
Axes de recherche
Qui suis-je (Who am I) ?
Dès ma thèse, j'ai toujours apprécié la "double casquette" d'enseignant-chercheur. Transmettre les connaissances, Diffuser les résultats de sa recherche et les Valoriser sont très importants pour moi. Mais avant tout, j'ai aussi choisi de travailler dans le service public, puisque boursière sur critères sociaux, j'ai pu utiliser cet ascenceur social. Même si ce n'était pas évident de se projeter dans le métier d'enseignant-chercheur, vu les concours à passer, et le peu de postes ouverts, c'est cela que je voulais faire. Et j'ai eu cette chance, dès la rentrée 1996-1997.
Since my thesis, I have always appreciated the "double hat" of teacher-researcher. Transmitting knowledge, disseminating the results of one's research and promoting them are very important to me. But above all, I also chose to work in the public service, since I was a scholarship holder based on social criteria, I was able to use this social elevator. Even if it was not easy to project myself into the profession of teacher-researcher, given the competitive exams to pass, and the few positions open, this is what I wanted to do. And I had this chance, from the start of the 1996-1997 academic year.
Carrière Administrative et Scientifique
Après un doctorat (Janvier 1996), j’ai réalisé un contrat post-doctoral au Max Planck Institut de Cologne (Allemagne) sur des problématiques d’hybridation in situ de transcrits de gènes impliqués dans tolérance à la sécheresse, qui a été écourté. Nommée Maître de Conférences à U-Lille (France) dès septembre 1996, j’ai obtenu mon HDR en Décembre 2001. Ma Recherche se déroule en trois temps. A) 1996-2008 sur la Dédifférenciation/Reprogrammation de cellules somatiques en cellules totipotentes végétales en prenant appui sur les modifications de leurs ArabinoGalactan Proteins pariétaux (collaboration avec IRD-CIRAD, Montpellier. B) 2008-2024, un changement d’UMR m’a permis de travailler sur une plante à fibre naturelle, le lin (équipe Plant Cell Wall Dynamics) sur la (dé)construction de la paroi cellulaire, en développant des approches de spectroscopies vibrationnelles RAMAN ou FT-IR (collaboration LASIRE, U-Lille). C) dès Janvier 2025, j’appliquerai ces approches technologiques spectrales et de cartographie chimique sur des questions évolutives (photosynthèse, Chromera), d’interactions durables (ver de Roscoff/Tetraselmis) ou sur les types/qualités/propriétés des amidons (équipe Integrative Biology on Storage Polysaccharides). Parallèlement, après la création du parcours Bilingue anglais dans la Licence mention Sciences de la Vie et la direction des études (2013-2019), je suis aussi enseignante en Biologie et Physiologie Végétale, Biologie Cellulaire et Embryologie végétales, et en Biologie Intégrative, particulièrement en Licence. J’apprécie aussi créer, développer et utiliser des innovations pédagogiques (conférences, une publication pédagogique internationale).
Administrative and Scientific Carreer
After a PhD (January 1996), I completed a postdoctoral contract at the Max Planck Institute in Cologne (Germany) on issues of in situ hybridization of gene transcripts involved in drought tolerance, which was shortened. Appointed Lecturer at U-Lille (France) in September 1996, I obtained my HDR in December 2001. My research takes place in three stages. A) 1996-2008 on the Dedifferentiation/Reprogramming of somatic cells into totipotent plant cells based on the modifications of their parietal ArabinoGalactan Proteins (collaboration with IRD-CIRAD, Montpellier. B) 2008-2024, a change of UMR allowed me to work on a natural fiber plant, flax (Plant Cell Wall Dynamics team) on the (de)construction of the cell wall, by developing RAMAN or FT-IR vibrational spectroscopy approaches (LASIRE collaboration, U-Lille). C) from January 2025, I will apply these spectral and chemical mapping technological approaches to evolutionary questions (photosynthesis, Chromera), sustainable interactions (Roscoff worm/Tetraselmis) or on the types/qualities/properties of starches (Integrative Biology on Storage Polysaccharides team). At the same time, after creating the Bilingual English course in the Bachelor's degree in Life Sciences and the direction of studies (2013-2019), I am also a teacher in Plant Biology and Physiology, Plant Cell Biology and Embryology, and in Integrative Biology, particularly in Bachelor's degree. I also enjoy creating, developing and using educational innovations (conferences, an international educational publication).
Research Key Words - Mots Clés de ma Recherche
Plant Cell Differentiation (Embryophytes, Algae) - Biologie Cellulaire Végétale (Plantes Terrestres, Algues)
Storage polymers: Starch, Cellulose, Lignin - Polymères de stockage: Amidon, Cellulose, Lignine
Vibrational Spectroscopy: Raman , FT-IR - Spectoscopie vibrationnelle: Raman, FT-IR
Chemical Cartography (subcellular level, cell, tissue)- Cartographie Chimique (subcellulaire, cellule, tissu)
Plant Histology and Cytology - Histologie et Cytologie végétales
Plant Embryology- Embryologie végétale
Micro-Algae - Micro Algue
Photosymbiosis - Photosymbiose
My team (Integrative Biology of Storage Polymers) main goals are:
- Elucidate polysaccharide metabolism and structural organisation;
- Explore their biodiversity
- Investigate the impact of stresses on polysaccharide metabolism and regulation
- Understand symbiosis mechanism between eucaryotes and photosynthetic organisms
I contribute to many projects according to my experimental skills. Hereafter the main topics in which I am involved.
Starch grain initiation and maintenance
Starch, a primary energy reserve in plants, accumulates in plastids as insoluble, semi-crystalline granules composed of amylose and amylopectin. The number, morphology, and positioning of these granules vary across tissues and species and are tightly regulated during chloroplast development. In Arabidopsis, starch granule initiation is largely dependent on the catalytic enzyme Starch Synthase 4 (SS4), which governs both granule number and shape. The noncatalytic protein PII1 (also known as MRC) was identified as a physical interactor of SS4 and appears essential for proper granule initiation without affecting granule morphology. Mutants lacking PII1 display a reduced number of starch granules per chloroplast but retain normal lenticular shapes, suggesting SS4 localization or activation is compromised. To dissect PII1’s role, double mutants (ss3 pii1 and ss4 pii1) were analyzed. ss3 pii1 still formed granules, implicating residual SS4 activity; ss4 pii1 had significantly reduced starch, indicating PII1’s role in supporting SS3-driven initiation. Parallel studies on ESV1 and LESV, two amylopectin-binding proteins, revealed that both bind semi-crystalline starch through a conserved C-terminal domain, with LESV uniquely mediating phase transition via conformational changes in its N-terminal region. Together, these findings underscore the complexity of starch granule initiation and structure maintenance and highlight distinct regulatory mechanisms involving SS isoforms and glucan-binding proteins.
Person in charge ot this topic: Fabrice.Wattebled@univ-lille.fr, Christophe.D-Hulst@univ-lille.fr
Starch grains in Stramenopile
Starch serves as the primary energy storage compound in plants, forming insoluble, semicrystalline granules composed mainly of amylopectin. The branched structure of amylopectin, with linear glucose chains forming double helices and branching points in amorphous regions, underpins granule architecture. In Arabidopsis thaliana, EARLY STARVATION 1 (ESV1) and LIKE EARLY STARVATION 1 (LESV) are two proteins implicated in maintaining granule structure and mediating glucan phase transitions. Both proteins contain a conserved tryptophan-rich C-terminal β-sheet domain essential for starch binding, though their N-terminal regions remain structurally undefined. Using biochemical and biophysical methods, we show that ESV1 and LESV bind amylopectin but not amylose. Importantly, only LESV interacts with amylopectin during starch biosynthesis, likely due to induced conformational changes in its N-terminal domain. Our findings elucidate the distinct molecular roles of ESV1 and LESV in starch granule formation. Additionally, bioinformatic analyses suggest a broader evolutionary context for glucan metabolism across Stramenopila. We detect alpha-glucan pathways in Opalozoa (excluding Blastocystis) and the absence of both alpha- and beta-glucan metabolism in sequenced Sagenista. Beta-glucan metabolism appears to have originated in Gyrista. These findings imply that the ancestral Stramenopile likely possessed dual glucan storage capabilities.
Person in charge ot this topic: Christophe.D-Hulst@univ-lille.fr
Evolution and Photosynthesis
The emergence of oxygenic photosynthesis in eukaryotes marks a pivotal evolutionary milestone that enabled plants to colonize environments previously inaccessible to their cyanobacterial ancestors. This process originated from a primary endosymbiotic event about 1.5 billion years ago, in which a cyanobacterium was engulfed by a biflagellate, phagotrophic eukaryotic cell. This led to the rise of Archaeplastida—Chloroplastida, Rhodophyceae, and Glaucophyta—who later became central players in global photosynthesis and contributed to complex secondary and tertiary endosymbioses. One intriguing group, the Chromerids (e.g., Chromera velia and Vitrella brassicaformis), closely related to dinoflagellates and apicomplexans, may provide insights into the photosynthetic ancestry of parasitic lineages. C. velia, in particular, exhibits unique adaptations to light-variable reef environments, such as red-light optimized complexes and specialized pigments like isofucoxanthin-like compounds. It also employs robust photoprotective strategies like non-photochemical quenching. The organism’s plastids support photosynthesis, while carbon metabolism is mainly regulated in the cytosol. Starch is stored cytosolically in the form of amylopectin, reflecting metabolic traits shared with red algae and Apicomplexa. These findings highlight the diversity and complexity of photosynthetic strategies among eukaryotes.
Person in charge of this topic: Ugo.Cenci@univ-lille.fr, Christophe.Colleoni@univ-lille.fr
Evolution and Photosymbiosis
Symsagittifera roscoffensis, an acoel belonging to the phylum Xenacoelomorpha, inhabits the intertidal zones of European coastlines and forms a unique and obligate photosymbiotic relationship with the green alga Tetraselmis convolutae. This association, first documented in the late 19th century, allows the worm to meet its nutritional needs exclusively through autotrophy, with no evidence of heterotrophic feeding. Juvenile worms hatch aposymbiotic and must acquire algal partners from their environment, a process that contributes to variation in symbiont composition across geographic populations.
While T. convolutae is the primary symbiont, alternative species of Tetraselmis have been observed in specific regions. The dynamics of photosymbiont acquisition—whether from algal pools seeded by previous generations or from locally available algae—remain an open question and raise the possibility of population-specific symbiotic adaptations.
This species’ symbiosis is part of a broader ecological and evolutionary phenomenon known as photosymbiosis, which spans numerous taxa and environments. From reef-building corals to pelagic plankton, these relationships involve a diverse array of hosts and algal symbionts, often acquired through horizontal transmission. Although generally mutualistic, the nature of photosymbiosis can vary along a spectrum of interaction types, depending on host-symbiont compatibility, nutrient exchange dynamics, and environmental context.
Understanding the biological and ecological factors underpinning the S. roscoffensis–Tetraselmis association offers insights into the mechanisms driving host-symbiont specificity, the evolution of autotrophy in animals, and broader symbiotic integration strategies in marine ecosystems.
Person in charge of this topic: Christophe.Colleoni@univ-lille.fr