@article {9333, title = {Aluminium-based galvanic anode impacts the photosynthesis of microphytobenthos and supports the bioaccumulation of metals released.}, journal = {Aquat Toxicol}, volume = {258}, year = {2023}, month = {2023 May}, pages = {106501}, abstract = {

Very few studies have looked at the potential biological effects of degradation products of galvanic anodes particularly on primary producers which are central to food webs in marine ecosystems. The galvanic anode cathodic protection system (GACP) is widely used to protect submerged metallic structures from corrosion. Aluminium (Al) and zinc (Zn) are the main constituents of galvanic anodes and are therefore released in the marine environment by oxidation process to form ions or oxy-hydroxides. The main objective of our study was to evaluate the effects of the metals released from an aluminium-based galvanic anode on microphytobenthos performance in term of biofilm growing through the analysis of photosynthetic parameters, the determination of chlorophyll and extracellular polymeric substances (EPS). The bioaccumulation of Al and Zn were measured in the microphytobenthic compartment collected at the surface of polyvinyl chloride (PVC) plates exposed during 13 days to seawaters enriched in different concentrations of metals released from dissolution of one anode. Determination of bioconcentration factors confirmed that the microphytobenthos has incorporated Al. A significative effect was observed on the Chl a concentration for the higher tested concentration ([Al]\ =\ 210.1\ {\textpm}\ 60.2\ {\textmu}g L\ \ ; [Zn]\ =\ 20.2\ {\textpm}\ 1.4\ {\textmu}g L\ \ ). The seawater exposed to the anode affected the MPB productivity (ETRII) with consequences on acclimatation light (Ek), absorption cross section of PSII (σ), F/F and NPQ. Regarding the EPS production, the anode degradation presented an impact on high and low molecular weight of both carbohydrates and protein fractions of microphytobenthos suggesting that EPS play an essential role in sequestering metal contaminants to maintain the integrity of the biological membranes and the functionality of the cellular organelles. The accumulation of Al released by GACP in microphytobenthos cells could lead to physiologic problems in photosynthetic organisms.

}, keywords = {Aluminum, Bioaccumulation, Ecosystem, Electrodes, Photosynthesis, Water Pollutants, Chemical, Zinc}, issn = {1879-1514}, doi = {10.1016/j.aquatox.2023.106501}, author = {Levallois, Alexandre and Vivier, Baptiste and Caplat, Christelle and Goux, Didier and Orvain, Francis and Lebel, Jean-Marc and Claquin, Pascal and Chasselin, L{\'e}o and Basuyaux, Olivier and Serpentini, Antoine} } @article {9279, title = {First isolation of Francisella halioticida strains from blue mussel (Mytilus edulis) in Normandy, France}, journal = {Journal of Invertebrate Pathology}, volume = {200}, year = {2023}, month = {09/2023}, pages = {107950}, issn = {00222011}, doi = {10.1016/j.jip.2023.107950}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0022201123000678}, author = {Bouras, H{\'e}l{\`e}ne and Quesnelle, Yann and Barozet, Alix and Goux, Didier and Blin, Jean-Louis and Savary, Manuel and C{\'e}line Zatylny-Gaudin and Maryline Houssin} } @article {9393, title = {Influence of nutrient enrichment on colonisation and photosynthetic parameters of hard substrate marine microphytobenthos}, journal = {Biofouling}, year = {2023}, month = {Feb-10-2023}, pages = {1 - 18}, abstract = {This study aimed to assess the influence of nutrient enrichment on the development of microalgal biofilm on concrete and PVC cubes. Three mesocosms were utilized to create a nutrient gradient over a period of 28 days. Various parameters including biomass, photosynthetic activity, microtopography, and extracellular polymeric substances (EPS) were measured. Imaging PAM techniques were employed to obtain surface-wide data. Results revealed that nutrient availability had no significant impact on Chl a biomass and the maximum quantum efficiency of PSII (Fv/Fm). The photosynthetic capacity and efficiency were minimally affected by nutrient availability. Interestingly, the relationship between microphytobenthic (MPB) biomass and photosynthesis and surface rugosity exhibited distinct patterns. Negative reliefs showed a strong correlation with Fv/Fm, while no clear pattern emerged for biomass on rough concrete structures. Overall, our findings demonstrate that under conditions of heightened eutrophication, biofilm photosynthesis thrives in the fissures and crevasses of colonized structures regardless of nutrient levels. This investigation provides valuable insights into the interplay between nutrient availability and surface rugosity.}, issn = {0892-7014}, doi = {10.1080/08927014.2023.2261852}, url = {https://www.tandfonline.com/doi/full/10.1080/08927014.2023.2261852}, author = {Vivier, Baptiste and Faucheux-Bourlot, Caroline and Orvain, Francis and Chasselin, L{\'e}o and Jolly, Orianne and Navon, Maxime and Boutouil, Mohamed and Goux, Didier and Dauvin, Jean-Claude and Pascal Claquin} } @article {9111, title = {New species of Pavlovophyceae (Haptophyta) and revision of the genera Exanthemachrysis, Rebecca and Pavlova}, journal = {European Journal of Taxonomy}, volume = {861}, year = {2023}, month = {08-03-2023}, pages = {21 - 47}, abstract = {The justification of the 4 genera that currently compose the class Pavlovophyceae is based on a low number of species and a relative paucity of available, traceable and referenced cultures. Previous integrative phylogeny work revealed strains that can refine and strengthen our knowledge of the genera\ in the class. The application of multiple light and electron microscopy techniques allowed us to prioritize\ the cytomorphological characters (pyrenoid, thylakoid, stigma, knob-scales, life stage / life cycle) used for\ the taxonomy of these algae and to describe two new species:\ Exanthemachrysis fresneliae\ Véron sp. nov. and\ Rebecca billardiae\ Véron sp. nov. Consequently, revisions of the two genera\ Exanthemachrysis\ Lepailleur emend. Véron and\ Rebecca\ Green emend. Véron were made. In addition, the genus\ Pavlova\ Butcher emend Véron is revised in the light of these characters. Particular emphasis is placed on the life\ stages and habitat of the species.}, keywords = {habitats, Haptophytes, New species, Phytoplankton, pyrenoid.}, issn = {2118-9773}, doi = {10.5852/ejt.2023.861.2063}, url = {https://europeanjournaloftaxonomy.eu/index.php/ejt/article/view/2063}, author = {Beno{\^\i}t V{\'e}ron and Rougier, Etienne and Taylor, Anthony and Goux, Didier} } @article {8109, title = {Influence of infrastructure material composition and microtopography on marine biofilm growth and photobiology}, journal = {Biofouling}, year = {2021}, month = {Apr-08-2022}, pages = {1 - 17}, issn = {0892-7014}, doi = {10.1080/08927014.2021.1959918}, url = {https://www.tandfonline.com/doi/full/10.1080/08927014.2021.1959918}, author = {Vivier, Baptiste and Pascal Claquin and Lelong, Christophe and Lesage, Quentin and Peccate, Mathias and Hamel, Bastien and Georges, Marine and Bourguiba, Amel and Sebaibi, Nassim and Boutouil, Mohamed and Goux, Didier and Dauvin, Jean-Claude and Francis Orvain} } @article {6117, title = {Histone Methylation Participates in Gene Expression Control during the Early Development of the Pacific Oyster .}, journal = {Genes (Basel)}, volume = {10}, year = {2019}, month = {2019 09 10}, abstract = {

Histone methylation patterns are important epigenetic regulators of mammalian development, notably through stem cell identity maintenance by chromatin remodeling and transcriptional control of pluripotency genes. But, the implications of histone marks are poorly understood in distant groups outside vertebrates and ecdysozoan models. However, the development of the Pacific oyster is under the strong epigenetic influence of DNA methylation, and histone-demethylase orthologues are highly expressed during . early life. This suggests a physiological relevance of histone methylation regulation in oyster development, raising the question of functional conservation of this epigenetic pathway in lophotrochozoan. Quantification of histone methylation using fluorescent ELISAs during oyster early life indicated significant variations in monomethyl histone H3 lysine 4 (H3K4me), an overall decrease in H3K9 mono- and tri-methylations, and in H3K36 methylations, respectively, whereas no significant modification could be detected in H3K27 methylation. Early in vivo treatment with the JmjC-specific inhibitor Methylstat induced hypermethylation of all the examined histone H3 lysines and developmental alterations as revealed by scanning electronic microscopy. Using microarrays, we identified 376 genes that were differentially expressed under methylstat treatment, which expression patterns could discriminate between samples as indicated by principal component analysis. Furthermore, Gene Ontology revealed that these genes were related to processes potentially important for embryonic stages such as binding, cell differentiation and development. These results suggest an important physiological significance of histone methylation in the oyster embryonic and larval life, providing, to our knowledge, the first insights into epigenetic regulation by histone methylation in lophotrochozoan development.

}, issn = {2073-4425}, doi = {10.3390/genes10090695}, author = {Alexandre Fellous and Lefranc, Lorane and Jouaux, Aude and Goux, Didier and Pascal Favrel and Riviere, Guillaume} } @article {6849, title = {Histone Methylation Participates in Gene Expression Control during the Early Development of the Pacific Oyster Crassostrea gigas}, journal = {Genes}, volume = {10}, year = {2019}, month = {Jan-09-2019}, pages = {695}, doi = {10.3390/genes10090695}, url = {https://www.mdpi.com/2073-4425/10/9/695}, author = {Fellous, Alexandre and Le Franc, Lorane and Jouaux, Aude and Goux, Didier and Pascal Favrel and Guillaume Rivi{\`e}re} } @article {8135, title = {Morphological and molecular criteria allow the identification of putative germ stem cells in a lophotrochozoan, the Pacific oyster Crassostrea gigas}, journal = {Histochemistry and Cell Biology}, volume = {151}, year = {2019}, month = {Jan-05-2019}, pages = {419 - 433}, issn = {0948-6143}, doi = {10.1007/s00418-018-1740-3}, url = {http://link.springer.com/10.1007/s00418-018-1740-3}, author = {Cherif-Feildel, Ma{\"e}va and Kellner, Kristell and Goux, Didier and Elie, Nicolas and Adeline, B{\'e}atrice and Lelong, Christophe and Clothilde Berthelin} } @article {5439, title = {Identification of a moronecidin-like antimicrobial peptide in the venomous fish Pterois volitans: Functional and structural study of pteroicidin-α.}, journal = {Fish and shellfish Immunology}, year = {2018}, pages = {318-324}, abstract = {

The present study characterizes for the first time an antimicrobial peptide in lionfish (Pterois volitans), a venomous fish. Using a peptidomic approach, we identified a mature piscidin in lionfish and called it pteroicidin-α. We detected an amidated form (pteroicidin-α- CONH2) and a non-amidated form (pteroicidin-α-COOH), and then performed their functional and structural study. Interestingly, the two peptides displayed different antibacterial and hemolytic activity levels. Pteroicidin-α-CONH2\ was bactericidal on human pathogens like Staphylococcus aureus or Escherichia coli, as well as on the fish pathogen Aeromonas salmonicida, while pteroicidin-α-COOH only inhibited their growth. Furthermore, the two peptides induced hemolysis of red blood cells from different vertebrates, namely humans, sea bass and lesser-spotted dogfish. Hemolysis occurred with low concentrations of pteroicidin-α-CONH2, indicating greater toxicity of the amidated form. Circular dichroism analysis showed that both peptides adopted a helical conformation, yet with a greater α-helix content in pteroicidin-α-CONH2. Overall, these results suggest that amidation strongly influences pteroicidin-α by modifying its structure and its physico-chemical characteristics and by increasing its hemolytic activity

}, author = {Houyvet, Baptiste and Yolande Bouchon-Navaro and Bouchon, Claude and Goux, Didier and Bernay, Beno{\^\i}t and Corre, Erwan and C{\'e}line Zatylny-Gaudin} } @article {5143, title = {Nutrient ratios influence variability in Pseudo-nitzschia species diversity and particulate domoic acid production in the Bay of Seine (France)}, journal = {Harmful Algae}, volume = {68}, year = {2017}, pages = {192 - 205}, abstract = {

The population dynamics of different Pseudo-nitzschia species, along with particulate domoic acid (pDA) concentrations, were studied from May 2012 to December 2013 in the Bay of Seine (English Channel, Normandy). While Pseudo-nitzschia spp. blooms occurred during the two years of study, Pseudo-nitzschia species diversity and particulate domoic acid concentrations varied greatly. In 2012, three different species were identified during the spring bloom (P. australis, P. pungens and P. fraudulenta) with high pDA concentrations (\~{}1400\ ng\ l-1) resulting in shellfish harvesting closures. In contrast, the 2013 spring was characterised by a P. delicatissima bloom without any toxic event. Above all, the results show that high pDA concentrations coincided with the presence of P. australis and with potential silicate limitation (Si:N\ \<\ 1), while nitrate concentrations were still replete. The contrasting environmental conditions between 2012 and 2013 highlight different environmental controls that might favour the development of either P. delicatissima or P. australis. This study points to the key role of Pseudo-nitzschia diversity and cellular toxicity in the control of particulate domoic acid variations and highlights the fact that diversity and toxicity are influenced by nutrients, especially nutrient ratios.

}, keywords = {Bloom dynamics, Domoic acid, English Channel, Nutrient ratios, Pseudo-nitzschia Species diversity}, issn = {1568-9883}, doi = {https://doi.org/10.1016/j.hal.2017.07.005}, url = {http://www.sciencedirect.com/science/article/pii/S1568988317300148}, author = {Thorel, Maxine and Pascal Claquin and Mathilde Schapira and Romain Le Gendre and Riou, Philippe and Goux, Didier and Le Roy, Bertrand and Raimbault, V and Deton-Cabanillas, Anne-Flore and Bazin, Pauline and Kientz-Bouchart, Val{\'e}rie and Juliette Fauchot} } @article {3864, title = {How Egg Case Proteins Can Protect Cuttlefish Offspring?}, journal = {PLoS One}, volume = {10}, year = {2015}, month = {2015}, pages = {e0132836}, abstract = {

Sepia officinalis egg protection is ensured by a complex capsule produced by the female accessory genital glands and the ink bag. Our study is focused on the proteins constituting the main egg case. De novo transcriptomes from female genital glands provided essential databases for protein identification. A proteomic approach in SDS-PAGE coupled with MS unveiled a new egg case protein family: SepECPs, for Sepia officinalis Egg Case Proteins. N-glycosylation was demonstrated by PAS staining SDS-PAGE gels. These glycoproteins are mainly produced in the main nidamental glands. SepECPs share high sequence homology, especially in the signal peptide and the three cysteine-rich domains. SepECPs have a high number of cysteines, with conserved motifs involved in 3D-structure. SDS-PAGE showed that SepECPs could form dimers; this result was confirmed by TEM observations, which also revealed a protein network. This network is similar to the capsule network, and it associates these structural proteins with polysaccharides, melanin and bacteria to form a tight mesh. Its hardness and elasticity provide physical protection to the embryo. In addition, SepECPs also have bacteriostatic antimicrobial activity on GRAM- bacteria. By observing the SepECP / Vibrio aestuarianus complex in SEM, we demonstrated the ability of these proteins to agglomerate bacteria and thus inhibit their growth. These original proteins identified from the outer egg case ensure the survival of the species by providing physical and chemical protection to the embryos released in the environment without any maternal protection.

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0132836}, author = {Cornet, Val{\'e}rie and Jo{\"e}l Henry and Goux, Didier and Duval, Emilie and Bernay, Beno{\^\i}t and Gildas Le Corguille and Corre, Erwan and C{\'e}line Zatylny-Gaudin} } @article {3508, title = {Hemocyte morphology and phagocytic activity in the common cuttlefish (Sepia officinalis).}, journal = {Fish Shellfish Immunol}, volume = {40}, year = {2014}, month = {2014 Oct}, pages = {362-73}, abstract = {

Little is known about the immune system of cephalopods, in spite of their many highly derived characters within the molluscan clade, including a vertebrate-like high-pressure closed circulatory system. Further the economic importance of cephalopod fisheries, potential for aquaculture, and use as ecotoxicology models demand a thorough understanding of their immune system. In this study, we present a comprehensive characterization of hemocytes in the common cuttlefish Sepia officinalis. Cytological stainings, electron microscopy- and flow cytometry-observations highlight a single granulocyte population with various densities of eosinophilic granules and unstained vesicles. These hemocytes contain acid phosphatase-, lysozyme- and proPO system enzymes, and have high activity in bead phagocytosis assays. Interestingly, bead pre-incubation in plasma results in time-dependent aggregation perhaps resulting from hemocyanin-coating, and decrease in phagocytosis. This study provides the basis for understanding hemocyte-mediated immunity in the common cuttlefish, and essential background for future studies on cephalopod immunity.

}, issn = {1095-9947}, doi = {10.1016/j.fsi.2014.07.020}, author = {Le Pabic, C and Goux, Didier and Guillamin, Maryline and Safi, Georges and Jean-Marc Lebel and Sim{\'e}oni Koueta-Noussith{\'e} and Antoine Serpentini} }