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Publications (58)
The European flat oyster (Ostrea edulis L.) is a native bivalve of the European coasts. Harvest of this species has declined during the last decades, because of the appearance of two parasites that have led to the collapse of the stocks and the loss of the natural oyster beds. O. edulis has been the subject of numerous studies and programs in popul...
Deep-sea mussels Bathymodiolus spp. harbor high densities of chemosynthetic bacterial symbionts located within their gill epithelial cells. Compared to non-symbiotic coastal mussel relatives of similar size, Bathymodiolus gills are considerably larger, a feature often considered an adaptation to symbiosis because it is related to the presence of in...
Ce rapport présente la version actualisée de la partie « Atlantique » du référentiel national des habitats marins benthiques en expliquant les modifications opérées. La mise à jour de la partie marine du référentiel européen EUNIS ainsi que les échanges avec les benthologues ont conduit à revoir les principes généraux de la typologie. La structure...
Symbiosis between Bathymodiolus and Gammaproteobacteria allows these deep-sea mussels to live in toxic environments such as hydrothermal vents and cold seeps. The quantity of endosymbionts within the gill-bacteriocytes appears to vary according to the hosts environment; however, the mechanisms of endosymbiont population size regulation remain obscu...
We provide the first detailed identification of Barents Sea cold seep frenulate hosts and their symbionts. Mitochondrial COI sequence analysis, in combination with detailed morphological investigations through both light and electron microscopy was used for identifying frenulate hosts, and comparing them to Oligobrachia haakonmosbiensis and Oligobr...
FISH image of non-symbiont hosting worm.
Epifluorescence micrograph of cross section of the trunk of a Spiochaetopterus worm from the crater site (sample 1124–6, negative control). Host/animal nuclei are stained with DAPI (blue). Hybridization did not occur and no fluorescence for bacterial symbionts were detected.
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Tube bacteria.
Close-up view of dense epibacterial colonies, seen on the anterior ends of the tubes of many individuals of the pingo and crater worms, giving a white, fuzzy appearance in videos and images.
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Sample list.
List of all the pingo and crater samples used in this study. Single individuals were often used for multiple analyses (different segments for different analyses), particularly if large or whole segments could be retrieved from the tubes. In addition to the pingo and crater samples, 13 worms from the Lofoten canyons, 1 from Nyegga, 1 fr...
Sampling locations.
Visual overviews of the sampling locations at the pingo sites (A-E) and crater sites (F-H). Images are video stills from the ROV 30K’s high definition video system. A: sample 1029 (blade core), B: sample 1078 (first scoop), C: sample 1078 (second scoop), D: 1078 (third scoop), E: 1078 (fourth scoop), F: 1123 (blade core), G: 112...
Bifurcated ‘egg string’ seen among the Oligobrachia clade.
Oligobrachia clade individual with the ‘egg string’ feature. A: Stereozoom view of the two arms of the feature, beginning immediately posterior of the diaphragm on the ventral side of the animal. The string is lined by a continuous blood vessel on either side of which lie the eggs. B: Semit...
Symbiosis between Bathymodiolus and Gammaproteobacteria enables these deep-sea mussels to live in toxic environments like hydrothermal vents and cold seeps. The quantity of endosymbionts within the gill bacteriocytes appears to vary according to the hosts environment. We investigated the hypothesis of a control of the endosymbionts density by apopt...
Vesicomyids live in endosymbiosis with sulfur-oxidizing bacteria and therefore need hydrogen sulfide to survive. They can nevertheless live in a wide range of sulfide and oxygen levels and depths, which may explain the exceptional diversity of this clam family in deep-sea habitats. In the Gulf of Guinea, nine species of vesicomyid clams are known t...
Suite à l’acquisition de nouvelles informations sur les habitats marins benthiques de Manche, de Mer du Nord et d’Atlantique, une mise à jour du référentiel national était nécessaire pour qu’il soit le reflet des connaissances actuelles. Ces nouvelles informations proviennent principalement des dernières campagnes d’exploration du milieu profond da...
Abstract Vesicomyid bivalves form dense clam beds in both deep-sea cold seeps and hydrothermal vents. The species diversity within this family raises questions about niche separation and specific adaptations. To compare their abilities to withstand hypoxia, we have studied the structure and function of erythrocyte hemoglobin (Hb) and foot myoglobin...
The diet of Pomatoschistus microps has been studied using both gut content and stable isotope analyses. In the Roscoff Aber Bay (Brittany, France), this fish is commonly found on sandy muddy intertidal flats. Gut content analyses were also interpreted using trophic indices. Owing to the large diversity of prey consumed, these indices emphasised the...
Bathymodiolus mussels associated with deep-sea hydrothermal vents and cold seeps harbor chemosynthetic endosymbiotic bacteria in bacteriocytes located in the gill epithelium. Two distinct morphotypes of gamma-proteobacteria, sulfur- and methane-oxidizing, have been identified and form a dual symbiosis in B. azoricus mussels from the Mid-Atlantic Ri...
Håkon Mosby mud volcano (HMMV) is one of the most active and most studied seep sites in European waters. Many authors have described its thermal activity, dynamic of mud flows, and geochemical and microbial processes. It is characterised by a concentric zonation of successive biogenic habitats related to an activity and geochemical gradient from it...
A new species of lamellibrachiid vestimentiferan, Lamellibrachia anaximandri n. sp., has been found in the Eastern Mediterranean, close to cold seeps of fluid carrying dissolved methane and sources of sulfide in superficial sediments. It occurs at about 1100 to 2100 m depth, on some of the mud volcanoes on the Anaximander Mountains, south of Turkey...
The branchial plume of the hydrothermal vent tubeworm Riftia pachyptila is the main organ by which this mouth- and gut-less tubeworm directly exchanges metabolites with its environment. We estimated the total branchial surface area per unit wet mass, termed the specific branchial surface area (SBSA), from planimetric measurements. Changes in the SB...
Animals inhabiting hydrothermal vents and cold seeps face conditions that are challenging for survival. In particular, these
two habitats are characterized by chronic hypoxia, sometimes reaching complete anoxia. The characteristics of the scaphognathite
and gills were studied in four species of shrimp and three species of crabs from hydrothermal ve...
Siboglinids are symbiotic polychete annelids having hemoglobins as essential oxygen- and sulfide-carriers for their endosymbiotic bacteria. We analyzed the structure of the hemoglobins from two species of siboglinids: the monilifera Sclerolinum contortum and the frenulata Oligobrachia webbi (i.e. haakonmosbiensis) from Norwegian cold seeps. Measure...
During the European Commission's Framework Six Programme, HERMES, we investigated three main areas along the European margin, each characterized by the presence of seep-related structures exhibiting different intensity of activity and biological diversity. These areas are: (1) the Nordic margin with the Håkon Mosby mud volcano and many pockmarks, (...
During the European Commission's Framework Six Programme, HERMES, we investigated three main areas along the European margin, each characterized by the presence of seep-related structures exhibiting different intensity of activity and biological diversity. These areas are: (1) the Nordic margin with the Hakon Mosby mud volcano and many pockmarks, (...
Peroxiredoxins (PRDXs) are a superfamily of thiol-dependent peroxidases found in all phyla. PRDXs are mechanistically divided into three subfamilies, namely typical 2-Cys, atypical 2-Cys, and 1-Cys PRDXs. To reduce peroxides, the N-terminal peroxidatic Cys of PRDXs is first oxidized into sulfenic acid. This intermediate is reduced by forming a disu...
The vestimentiferan annelid Riftia pachyptila forms dense populations at hydrothermal vents along the East Pacific Rise at a depth of 2600 m. It harbors CO(2)-assimilating sulfide-oxidizing bacteria that provide all of its nutrition. To find specific host transcripts that could be important for the functioning of this symbiosis, we used a subtracti...
The vestimentiferan tubeworm Ridgeia piscesae Jones, 1985 from the Juan de Fuca Ridge is a morphologically plastic species with two contrasted ecotypes. The "chimney-dwelling" ecotype lives along the sides of active hydrothermal chimneys, where temperature and sulfide concentrations are high, but oxygen concentrations are low. Its morphology corres...
A new species of vestimentiferan tubeworm belonging to the genus Escarpia is described from cold seeps off the western coast of Africa. The description is based on two collections (one of 180 animals, the other of 30 animals) using both morphological and molecular techniques. Morphologically, the African tubeworms are very similar to Escarpia lamin...
The symbiotic tubeworm Riftia pachyptila needs to fuel its chemoautotrophic symbiotic bacteria with inorganic carbon. CO(2) is transported from the surrounding water to the bacteriocytes located in the trophosome, through the branchial plume and the body fluids. Previous studies have demonstrated the implication of carbonic anhydrase (CA) and proto...
The hydrothermal-vent tubeworm Riftia pachyptila relies entirely on its intracellular chemoautotrophic symbionts to sustain its metabolism. The host must therefore provide them with inorganic metabolites, including carbon. This study describes a tool for studying cell processes occurring in a bacteria-containing cell by the dissociation of trophoso...
The Vestimentifera have in their branchial plume a centralized structure, the obturaculum, supporting the respiratory lamellae and enabling the worm to close its tube. We have studied its structure in Riftia pachyptila, focusing on the relations between its main parts: epidermis, muscles and extracellular matrix (ECM). The epidermis is supported by...
Olomoucine (2-(2-hydroxyethylamino)-6-benzylamino-9-methylpurine) has been recently described as a competitive inhibitor (ATP-binding site) of the cell cycle regulating p34cdc2/cyclin B, p33cdk2/cyclin A and p33cdk2/cyclin E kinases, the brain p33cdk5 p35 kinase and the ERK1AP-kinase. The unusual specificity of this compound towards cell cycle regu...
This chapter focuses on neuropeptides in the amphibian brain emphasizing neuroendocrine relations. Neuropeptides are synthesized as multiple molecular variants, and they may play different roles in various organisms. An analysis of the distribution of neuropeptides in vertebrates and their phenotypic plasticity, especially during development, leads...
We have used an antibody specific for phosphotyrosine to investigate protein phosphorylation on tyrosine during hormone-induced maturation of starfish oocytes. Analysis of immunoprecipitates from cortices of in vivo labeled Marthasterias glacialis oocytes revealed the presence of labeled phosphotyrosine-containing proteins only after hormone additi...
It has been reported that the starfish homolog of the fission yeast cdc2 protein is a component of maturation promoting factor (MPF) that controls entry of eukaryotic cells into M-phase. The p34cdc2
protein is phosphorylated during interphase and dephosphorylated during M-phase. We show that starfish p34cdc2
is phosphorylated in vivo on tyrosine, t...
Distribution and quantification of PRL in the pituitary gland of the frog Rana ridibunda were investigated using a high-affinity antiserum raised against bullfrog prolactin (PRL). The immunoreactive PRL-producing cells were distributed throughout the pars distalis, the highest density of cells being observed in the rostral region of the adenohypoph...
The distribution of melanin-concentrating hormone (MCH) in the central nervous system of the dogfish Scyliorhinus canicula was determined by indirect immunofluorescence and peroxidase-anti-peroxidase techniques, using an antiserum raised against synthetic salmon MCH. Three groups of MCH-positive cell bodies were localized in the posterior hypothala...
Gonadotropin-releasing-hormone (GnRH)-associated peptide (GnRH-AP) is a 56 amino acid neuropeptide derived from the GnRH prohormone. GnRH-AP corresponds to the C-terminal fragment flanking the GnRH peptide. Using an antiserum raised against human GnRH-AP [1-56], or against human GnRH, we have investigated the neuronal systems containing either pept...
The distribution of melanin concentrating hormone (MCH) in the central nervous system of the locust Locusta migratoria was studied by the indirect immunofluorescence technique, using antibodies against salmon MCH. Most MCH-immunoreactive perikarya were found in the optic lobes at both sides of the brain, dorsally with respect to the lamina ganglion...
The eel A. anguilla offers several properties of a useful bioindicator such as its worldwide distribution, abundance, size, long life span and euryhalinity. This last characteristic which is more marked than in all other bioindicators allows the comparison of the contamination levels of marine and estuarine areas as well as river basins, according...
By means of the peroxidase-anti-peroxidase technique, the distribution of neuropeptide tyrosine (NPY) and its C-terminal flanking peptide (C-PON) has been studied on serial sections of the brain and pituitary of the frog Rana ridibunda. Throughout the brain, NPY and C-PON-immunoreactive perikarya exhibited a remarkable co-distribution. These two pe...
Coexistence of MCH- and alpha-MSH-like peptides in specific neurons of the frog hypothalamus has been investigated on serial frozen sections using the indirect immunofluorescence method. In the anterior region of the preoptic nucleus, perikarya containing MCH- and alpha-MSH-immunoreactive materials were co-distributed and the two peptides were gene...
The presence of atrial natriuretic factor (ANF)-like material in the hypothalamo-pituitary complex of the frog (Rana ridibunda) was studied by means of indirect immunofluorescence and immunogold techniques. In the hypothalamus, numerous ANF-positive cell bodies were located in the preoptic nucleus, the lateral forebrain bundle and the dorsal infund...
The distribution of melanin-concentrating hormone (MCH) in the central nervous system of the frog Rana ridibunda was determined by the indirect immunofluorescence technique using antibodies against synthetic salmon MCH, generated in rabbits. The most prominent group of MCH-like containing perikarya was detected in the preoptic nucleus. Comparativel...
This study combines trace-metal analysis with an immunofluorescent detection of a methionine-enkephalin-like substance in the digestive gland of the shore crab, Carcinus maenas L. The crabs were taken from two sites: Saint Nazaire and Le Croisic, the first being polluted in comparison to the second. The experimental crabs were also taken in Le Croi...
Using the indirect immunofluorescence technique, methionine-enkephaline-like, alpha- and beta-endorphin-like peptides were detected on whole body sections of Mytilus edulis L. Met-enkephalin-like immunoreactivity was localized in the epithelium of the digestive tract, in the hepatopancreas, and in the nervous system. The immunoreactive cell bodies...
Five antisera against insulin (Ins), glucagon (Glu), somatostatin (SRIF), met-enkephalin (met-enk), and serotonin (5-HT) were used for immunofluorescence detection of endocrine cells in pancreas and gastrointestinal tract (GIT) of the European eel (Anguilla anguilla L.) at three stages of development (leptocephalic larva, glass-eel, and adult eel)....
