A5045648349- Marine and coastal plant biology
- Diatoms and Algae Research
- Plant Molecular Biology Research
- Algal biology and biofuel production
- Plant Reproductive Biology
- Biocrusts and Microbial Ecology
- Seaweed-derived Bioactive Compounds
- Photosynthetic Processes and Mechanisms
- Microbial Community Ecology and Physiology
- Polar Research and Ecology
- Echinoderm biology and ecology
- Protist diversity and phylogeny
- Marine Biology and Environmental Chemistry
- Plant nutrient uptake and metabolism
- Polysaccharides and Plant Cell Walls
- Plant and animal studies
- Turfgrass Adaptation and Management
- Coastal wetland ecosystem dynamics
- Photoreceptor and optogenetics research
- ATP Synthase and ATPases Research
- Metabolism, Diabetes, and Cancer
- Mitochondrial Function and Pathology
- Microtubule and mitosis dynamics
Station Biologique de Roscoff
2007-2025
Sorbonne Université
2007-2024
Centre National de la Recherche Scientifique
2007-2024
Laboratoire de Biologie Intégrative des Modèles Marins
2019-2024
Friedrich-Alexander-Universität Erlangen-Nürnberg
2012-2024
Morpho (United States)
2024
Université Paris Cité
2012
Centre de Gestion Scientifique
2012
Umeå Plant Science Centre
2010
Laboratoire des Biomolécules
2008
The genome of Ectocarpus, a model organism for brown algae, has been sequenced. Brown algae are complex photosynthetic organisms that have adapted to life in rocky coastal environments. Genome analysis sheds light on this adaptation and reveals an extended set light-harvesting pigment biosynthesis genes novel metabolic processes such as halide metabolism. Comparative genomic analyses highlight the likely importance family receptor kinases related molecules evolution multicellularity plants,...
Abstract Ectocarpus siliculosus is a small brown alga that has recently been developed as genetic model. Its thallus filamentous, initially organized main primary filament composed of elongated cells and round cells, from which branches differentiate. Modeling its early development suggests the involvement very local positional information mediated by cell-cell recognition. However, this model also indicates an additional mechanism required to ensure proper organization branching pattern. In...
Brown algae are plant multi-cellular organisms occupying most of the world coasts and essential actors in constitution ecological niches at shoreline. Ectocarpus siliculosus is an emerging model for brown algal research. Its genome has been sequenced, several tools being developed to perform analyses different levels cell organization, including transcriptomic expression analyses. Several topics, physiological responses osmotic stress exposure contaminants solvents studied order better...
The use of the moss Physcomitrella patens as a model system to study plant development and physiology is rapidly expanding. strategic position P. within green lineage between algae vascular plants, high efficiency with which transgenes are incorporated by homologous recombination, advantages associated haploid gametophyte representing dominant phase life cycle, simple structure protonemata, leafy shoots rhizoids that constitute gametophyte, well readily accessible high-quality genome...
The initiation of embryogenesis in the kelp Saccharina latissima is accompanied by significant anisotropy cell shape. Using monoclonal antibodies, we show that this coincides with a spatio-temporal pattern accumulation alginates wall zygote and embryo. Alginates rich guluronates as well sulphated fucans homogeneous distribution embryo throughout Phase I embryogenesis, but mannuronate accumulate mainly on sides embryo, disappearing enlarges at start II. This depends presence cortical actin...
Abstract Brown algae are multicellular marine organisms evolutionarily distant from both metazoans and land plants. The molecular or cellular mechanisms that govern the developmental patterning in brown poorly characterized. Here, we report first morphogenetic mutant, étoile (etl), produced algal model Ectocarpus siliculosus. Genetic, cellular, morphometric analyses showed a single recessive locus, ETL, regulates cell differentiation: etl cells display thickening of extracellular matrix...
Abstract Ectocarpus is a filamentous brown alga, which cell wall composed mainly of alginates and fucans (80%), two non-crystalline polysaccharide classes. Alginates are linear chains epimers 1,4-linked uronic acids, β-D-mannuronic acid (M) α-L-guluronic (G). Previous physico-chemical studies showed that G-rich alginate gels stiffer than M-rich when prepared in vitro with calcium. In order to assess the possible role , we first immunolocalised or using specific monoclonal antibodies along...
We used an in silico approach to predict microRNAs (miRNAs) genome-wide the brown alga Ectocarpus siliculosus. As algae are phylogenetically distant from both animals and land plants, our relied on features shared by all known organisms, excluding sequence conservation, genome localization pattern of base-pairing with target. predicted between 500 1500 miRNAs candidates, depending values energetic parameters filter potential precursors. Using quantitative polymerase chain reaction assays, we...
Pollen tube growth is essential for plant reproduction and represents a widely employed model to investigate polarized cell expansion, process important morphogenesis development. Cellular regulatory mechanisms underlying pollen elongation are under intense investigation, which stands greatly benefit from comprehensive understanding of global gene expression profiles in tubes. Here, RNA sequencing technology was applied de novo assemble Nicotiana tabacum male gametophytic transcriptome...
The distant phylogenetic position of brown macroalgae from the other multicellular phyla offers opportunity to study novel and alternative developmental processes involved in establishment multicellularity. At present, however, very little information is available about patterning this group. Ectocarpus siliculosus (Dillwyn) Lyngb. has uniseriate filaments displays one simplest architectures Phaeophyceae. aim was decipher morphogenetic steps that lead development sporophyte. We carried out a...
Tip growth of pollen tubes, root hairs and apical cells moss protonemata is controlled by ROP (Rho plants) GTPases, which were shown to accumulate at the plasma membrane these cells. However, most localization patterns reported in literature are based on fluorescent protein tagging need be interpreted with caution, as fusion proteins generally overexpressed undefined levels, commonly without assessing effects tip growth. ROP-GEFs, important regulators activity, also described during date...
RHO guanosine triphosphatases are important eukaryotic regulators of cell differentiation and behavior. Plant ROP (RHO plant) family members activate specific, incompletely characterized downstream signaling. The structurally simple land plant Physcomitrium patens is missing homologs key animal flowering effectors but contains a single CRIB (CDC42/RAC interactive binding)-domain-containing RIC (ROP-interacting CRIB-containing) protein (PpRIC). Protonemal P. filaments elongate based on...
Flagellated cells are of great evolutionary importance across animal and plant species. Unlike higher plants, flagellated involved in reproduction macro-algae as well early diverging land plants. Euglena gracilis is an emerging model organism. The current study reports that a specific calmodulin (CaM2) gravitaxis E. interacts with conserved flagellar protein, EgPCDUF4201. subsequent molecular analysis showed clearly EgPCDUF4201 also gravitaxis. We performed subcellular localization CaM2...
Early development of the filamentous brown alga Ectocarpus siliculosus (Dillwyn) Lyngbye involves two cell types that are arranged in a polymorphic, but constrained, pattern. The present study aimed to decipher cellular processes responsible for establishment this Thorough observations characterised five different events division and differentiation occurred during early development. hypothesis local control is these was tested. To do so, Ectomat, stochastic automaton which each only...
Ectocarpus siliculosus is being developed as a model organism for brown algal genetics and genomics.1,2 Brown algae are phylogenetically distant from the other multicellular phyla (green lineage, red algae, fungi metazoan)3 therefore might offer opportunity to study novel alternative developmental processes that lead establishment of multicellularity. E. develops uniseriate filaments, thereby displaying one simplest architectures among organisms.4 The young sporophyte grows primary filament...
Euglena gracilis is a photosynthetic flagellate. To acquire suitable position in its surrounding aquatic environment, it exploits light and gravity primarily as environmental cues. Several physiological studies have indicated fine-tuned relationship between sensing (gravitaxis) E. gracilis. However, the underlying molecular mechanism largely unknown. The photoreceptor photoactivated adenylyl cyclase (PAC) has been studied for over decade. Nevertheless, no direct/indirect interaction partner...
Abstract The initiation of embryogenesis in the kelp Saccharina latissima is accompanied by significant anisotropy cell shape. Using monoclonal antibodies, we show that this coincides with a spatio-temporal pattern accumulation alginates wall zygote and embryo. Alginates rich guluronates as well sulphated fucans homogeneous distribution embryo throughout Phase I embryogenesis, but mannuronate accumulate mainly on sides embryo, disappearing enlarges at start II. This depends presence cortical...
<title>Abstract</title> The initiation of embryogenesis in the kelp Saccharina latissima is accompanied by significant anisotropy cell shape. Using monoclonal antibodies, we show that this coincides with a spatio-temporal pattern accumulation alginates wall zygote and embryo. Alginates rich guluronates as well sulphated fucans homogeneous distribution embryo throughout Phase I embryogenesis, but mannuronate accumulate mainly on sides embryo, disappearing enlarges at start II. This depends...
Abstract RHO GTPases are key regulators of cellular and developmental processes in most eukaryotic organisms. ROPs (RHO plants) constitute a plant-specific subfamily. ROP families expanded functionally diversified during the evolution structurally complex vascular plants, but generally contain few members non-vascular plants with ancient features. In proteins required for cell polarization, directional expansion, mitotic plate positioning. All these impaired by disruption PpROP activity moss...
Abstract The brown alga Ectocarpus is a filamentous seaweed that grows by tip growth and branching. In the morphometric mutant etoile , slower than in WT eventually stops. this paper, we show causal mutation null bi-domain BAR-RhoGAP gene. By quantitative RT-PCR, showed ETOILE ubiquitously expressed prostrate filaments of sporophyte, downregulated mutant. We immunolocalised both domains protein as well RAC1, known target Rho-GAP enzymes. Thus, would be localised at apical cell dome where it...