Researcher CNRS

CELL WALL BIOLOGY IN MACROALGAE

MY RESEARCH PROJECT

Macroalgae and land plants share convergent evolutionary traits, such as multicellularity and a polysaccharide-rich cell-wall surrounding their cells. These two features are intrinsically interlinked as the development of an adherent cell-wall allowed the transition from cellular autonomy to cellular cooperation, and therefore multicellularity. For land plants we have an extensive understanding of the structures and functions of the cell wall, but such knowledge is scarce in macroalgae. Being evolutionary distant from land plants, marine algae offer attractive models to study the bases of developmental mechanisms in eukaryotes.

My research interests are focused on marine algal cell walls in relation to their biological functions. The brown algae are my current main models. In the Fucus embryo we study the role of the cell wall in the polar axis establishment during the first cell-division. In Ectocarpus we study the role of the cell wall during cell expansion, cell differentiation and life-cycle transition. We are also interested in understanding the cell wall variations that occur in brown algae during environmental changes such as salinity change.

TOOLS AND TECNHIQUES

The cell wall assembly of these constituents is studied in situ by immunohistochemistry techniques coupled with fluorescence and electron microscopy. To do this we developed specific probes for our targeted algal cell wall polysaccharides: specific recombinant carbohydrate-binding proteins from marine bacteria (heterologously expressed and biochemically characterised) and monoclonal antibodies (in collaboration with Prof. Paul Knox in Leeds-UK). In particular we maintain the cell lines producing the Brown Algal Monoclonal (BAM) antibodies against sulfated fucans (BAM1-4) and alginates (BAM6-11) (for details see Torode et al., 2015; 2016 -mentioned below). We also work on gaining an exhaustive view of the cell wall compounds in macroalgae using high throughput techniques (i e. sequential cell-wall extractions and oligosaccharide profiling, and specific antibody-based glycoarrays in collaboration with Prof. William Willats in Newcastle -UK).


PEOPLE

Amandine Siméon (PhD student)
Kevin Hardouin (post-doctoral fellow)
Murielle Jam (lab technician)

former -Delphine Duffieux (lab technician)

 

 

Publications

A SELECTION IS SHOWN

Deniaud-Bouët E, Hardouin K, Potin P, Kloareg B, Hervé C (2017). A review about brown algal cell walls and fucose-containing sulfated polysaccharides: Cell wall context, biomedical properties and key research challenges. Carbohydrate polymers 175, 395-408.

Siméon A, Hervé C (2017). Isolation of Fucus serratus Gametes and Cultivation of the Zygotes. Bio-protocol 7(14): e2408.

Salmeán AA, Duffieux D, Harholt J, Qin F, Michel G, Czjzek M, Willats WGT, Hervé C (2017). Insoluble (1 → 3), (1 → 4)-β-D-glucan is a component of cell walls in brown algae (Phaeophyceae) and is masked by alginates in tissues. Scientific Reports, 7(1), 2880

Torode AT, Siméon A, Marcus SE, Jam M, Le Moigne M-A, Duffieux D, Knox JP, Hervé C (2016). Dynamics of cell wall assembly during early embryogenesis in the brown alga Fucus. Journal of Experimental Botany. 61(21): 6089-6100

Ropartz D, Giuliani A, Fanuel M, Hervé C, Czjzek M, Rogniaux H (2016). Online Coupling of High-Resolution Chromatography with Extreme Uv Photon Activation Tandem Mass Spectrometry: Application to the Structural Investigation of Complex Glycans by Dissociative Photoionization. Analytica Chimica Acta. 933: 1-9

Fischl R, Bertelsen K, Gaillard F, Coelho S, Michel G, Klinger M, Boyen C, Czjzek M, Hervé C (2016). The cell wall active mannuronan C5-epimerases in the model brown alga Ectocarpus: from gene context to recombinant protein. Glycobiology. 26(9): 973-983

Hervé C, Siméon A, Jam M, Cassin A, Johnson KL, Salmeán AA, Willats WG, Doblin MS, Bacic A, Kloareg B (2016). Arabinogalactan proteins have deep roots in eukaryotes: identification of genes and epitopes in brown algae and their role in Fucus serratus embryo development. New Phytologist. 209: 1428–1441

Ficko-Blean E, Hervé C, Michel G (2015). Sulfated sugars from the sea: biosynthesis and remodelling of sulfated macroalgal cell wall polysaccharides. Perspectives in Phycology 2(1): 51-64.

Torode TA, Marcus SE, Jam M, Tonon T, Blackburn RS, Hervé C, Knox JP (2015). Monoclonal antibodies directed to fucoidan preparations from brown algae. PLoS One 10(2): e0118366.

Ropartz D, Giuliani A, Hervé C, Geairon A, Jam M, Czjzek C, Rogniaux H (2015). High-Energy Photon Activation Tandem Mass Spectrometry Provides Unprecedented Insights into the Structure of Highly Sulfated Oligosaccharides Extracted from Macroalgal Cell Walls. Analytical Chemistry 87(2): 1042-49.

Tsirigoti A, Beakes G, Hervé C, Gachon CM, Katsaros C (2014) Attachment, penetration and early host defense mechanisms during the infection of filamentous brown algae by Eurychasma dicksonii. Protoplasma: 1-12.

Deniaud-Bouët E, Kervarec N, Michel G, Tonon T, Kloareg B, Hervé C (2014) Chemical and enzymatic fractionation of cell walls from Fucales: insights into the structure of the extracellular matrix of brown algae. Annals of Botany 114: 1203-1216.

Popper ZA, Michel G, Hervé C, Domozych D, Willats WGT, Tuohy MG, Kloareg B, Stengel DB (2011). Evolution and Diversity of Plant Cell Walls: From Algae to Flowering Plants. Annu Rev Plant Biol. 62: 567-590.