%0 Journal Article %J Environmental Microbiology %D 2017 %T Physiological adjustments and transcriptome reprogramming are involved in the acclimation to salinity gradients in diatoms %A Adrien Bussard %A Corre, Erwan %A Cédric Hubas %A Duvernois‐Berthet, Evelyne %A Gildas Le Corguille %A Jourdren, Laurent %A Coulpier, Fanny %A Pascal Claquin %A Pascal Jean Lopez %X

Salinity regimes in estuaries and coastal areas vary with river discharge patterns, seawater evaporation, the morphology of the coastal waterways, and the dynamics of marine water mixing. Therefore, microalgae have to respond to salinity variations at time scales ranging from daily to annual cycles. Microalgae may also have to adapt to physical alterations that induce the loss of connectivity between habitats and the enclosure of bodies of water. Here, we integrated physiological assays and measurements of morphological plasticity with a functional genomics approach to examine the regulatory changes that occur during the acclimation to salinity in the estuarine diatom Thalassiosira weissflogii. We found that cells exposed to different salinity regimes for a short or long period presented adjustments in their carbon fractions, silicon pools, pigment concentrations and/or photosynthetic parameters. Salinity-induced alterations in frustule symmetry were observed only in the long-term cultures. Whole transcriptome analyses revealed a down-regulation of nuclear and plastid encoded genes during the long-term response and identified only a few regulated genes that were in common between the short- and long-term responses. We propose that in diatoms, one strategy for acclimating to salinity gradients and maintaining optimal cellular fitness could be a reduction in the cost of transcription. This article is protected by copyright. All rights reserved.

%B Environmental Microbiology %V 19 %P 909-925 %8 5 %G eng %U http://dx.doi.org/10.1111/1462-2920.13398 %N 3 %R 10.1111/1462-2920.13398 %0 Journal Article %J PLoS One %D 2015 %T How Egg Case Proteins Can Protect Cuttlefish Offspring? %A Cornet, Valérie %A Joël Henry %A Goux, Didier %A Duval, Emilie %A Bernay, Benoît %A Gildas Le Corguille %A Corre, Erwan %A Céline Zatylny-Gaudin %X

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.

%B PLoS One %V 10 %P e0132836 %8 2015 %G eng %N 7 %R 10.1371/journal.pone.0132836 %0 Journal Article %J Process Biochemistry %D 2015 %T Molecular characterization of peptide fractions of a Tilapia (Oreochromis niloticus) by-product hydrolysate and in vitro evaluation of antibacterial activity %A Robert, Marie %A Céline Zatylny-Gaudin %A Fournier, Vincent %A Corre, Erwan %A Gildas Le Corguille %A Bernay, Benoît %A Joël Henry %B Process Biochemistry %V 50 %P 487-492 %G eng %N 3 %0 Journal Article %J Dev Comp Immunol %D 2015 %T The Toll/NF-κB pathway in cuttlefish symbiotic accessory nidamental gland. %A Cornet, Valérie %A Joël Henry %A Corre, Erwan %A Gildas Le Corguille %A Céline Zatylny-Gaudin %X

The female genital apparatus of decapod cephalopods contains a symbiotic accessory nidamental gland (ANG) that harbors bacterial symbionts. Although the ANG bacterial consortium is now well described, the impact of symbiosis on Sepia officinalis innate immunity pathways remains unknown. In silico analysis of the de novo transcriptome of ANG highlighted for the first time the existence of the NF-κB pathway in S. officinalis. Several signaling components were identified, i.e. five Toll-like receptors, eight signaling cascade features, and the immune response target gene iNOS, previously described as being involved in the initiation of bacterial symbiosis in a cephalopod gland. This work provides a first key for studying bacterial symbiosis and its impact on innate immunity in S. officinalis ANG.

%B Dev Comp Immunol %V 53 %P 42-46 %8 2015 Jul 2 %G eng %N 1 %R 10.1016/j.dci.2015.06.016 %0 Journal Article %J J Proteomics %D 2014 %T Dual role of the cuttlefish salivary proteome in defense and predation. %A Cornet, Valérie %A Joël Henry %A Corre, Erwan %A Gildas Le Corguille %A Zanuttini, Bruno %A Céline Zatylny-Gaudin %X

UNLABELLED: We characterized the proteome of the posterior salivary glands of the cephalopod S. officinalis by combining de novo RNA sequencing and mass spectrometry. In silico analysis of the transcriptome revealed the occurrence of three main categories of proteins: enzymes, immune factors and toxins. Protein identification by SDS-PAGE and MALDI-TOF/TOF confirmed the occurrence of proteins essential to venom-like enzymes: peptidase S1 under four isoforms, phospholipase A2 and two toxins. The first toxin is a cystein rich secreted protein (CRISP), a common toxin found in all venomous animals. The second one is cephalotoxin, which is specific to decabrachia cephalopods. Secretions of the posterior salivary glands are transported to the cephalopodium; they are involved in prey catching but also in gamete storage, fertilization and egg-laying. The paralyzing activity and the antimicrobial effect of saliva suggest a dual role in predation and in immune defense in cuttlefish.

BIOLOGICAL SIGNIFICANCE: The originality of this study lies in the use of a transcriptomic approach (de novo RNA sequencing) coupled to a proteomic approach to get an overview of posterior salivary glands in S. officinalis. In cephalopods, these glands are involved in predation, more precisely in paralyzing preys and digesting them. Our in silico analysis equally reveals a role in immune defense as observed in mammals' saliva. Our study also shows the specificity of cuttlefish venom, with the identification of cephalotoxins, proteins that are not found in octopuses. Finally, we show that cuttlefish saliva is a complex mixture that has antibacterial and crippling properties, but no lethal effect.

%B J Proteomics %V 108 %P 209-22 %8 2014 Aug 28 %G eng %1 http://www.ncbi.nlm.nih.gov/pubmed/24892799?dopt=Abstract %R 10.1016/j.jprot.2014.05.019 %0 Journal Article %J J Biotechnol %D 2014 %T Transcriptomic and peptidomic analysis of protein hydrolysates from the white shrimp (L. vannamei). %A Robert, Marie %A Céline Zatylny-Gaudin %A Fournier, Vincent %A Corre, Erwan %A Gildas Le Corguille %A Bernay, Benoît %A Joël Henry %X

An RNAseq approach associated to mass spectrometry was conducted to assess the composition, molecular mass distribution and primary sequence of hydrolytic peptides issued from hydrolysates of white shrimp (Litopenaeus vannamei) by-products. High performance size exclusion chromatography (HPSEC) analyses indicated that 69.2% of the 214-nm-absorbing components had apparent molecular masses below 1000 Da, and 88.3% below 2000 Da. OFFGEL-nLC-MALDI-TOF/TOF and nLC-ESI-MS/MS analyses led to the identification of 808 peptides based on the NCBI EST databank (161,397 entries) completed by the new L. vannamei databank (58,508 entries) that we created from the RNAs of tissues used for hydrolysate production. Whereas most of hydrolytic peptides have a MW below 2000 Da, preliminary investigations of antimicrobial properties revealed three antibacterial fractions that demonstrate functional activities. The abundance of small peptides as well as the biological activities detected could imply very interesting applications for shrimp hydrolysate in the field of aquaculture feeding.

%B J Biotechnol %V 186 %P 30-7 %8 2014 Sep 30 %G eng %1 http://www.ncbi.nlm.nih.gov/pubmed/24998765?dopt=Abstract %R 10.1016/j.jbiotec.2014.06.020