Celine Zatylny-Gaudin

• Professor
• Université de Caen - Normandie

Study of the diet of squid is hampered by the fact that these animals masticate their prey prior to ingestion and do not necessarily ingest the hard parts that allow the identification of prey remains present in the stomach. The result is a large percentage of prey in stomach contents that can be identified only according to broad categories (e.g.,...

The bacterium Francisella halioticida, known to induce francisellosis in abalone and Yesso scallop, is suspected of being involved in the blue mussel mortalities observed in France. Recently, several isolates of F. halioticida were obtained from moribund mussels and categorized into two type strains, FR21 and FR22. Two other strains, AG1 and AG3, d...

Sacculina carcini is an endoparasite of the green crab, Carcinus maenas. This parasite induces behavioural changes in its host and affects its metabolism by inhibiting moulting and reproduction. Using a proteomic approach in mass spectrometry, we studied the haemolymph proteomes of healthy and parasitized wild green crabs from Brittany, France to i...

Mass mortality events affecting the blue mussels Mytilus edulis have been observed in France since 2014. The DNA of the bacterium Francisella halioticida, reported as pathogen of giant abalone (Haliotis gigantea) and Yesso scallop (Mizuhopecten yessoensis) has been detected recently in mussels from areas suffering mortalities. Isolation of this bac...

The development of de novo sequencing tools has led to the massive production of genomes and transcriptomes from many unconventional animal models. To tackle this huge flow of data, PepTraq brings together many functionalities generally scattered in multiple tools, so that sequences can be filtered on the basis of multiple criteria. It is particula...

The cuttlefish (Sepia officinalis) is a Cephalopod mollusk that lives in the English Channel and breeds in coastal spawning grounds in spring. A previous work showed that the control of egg-laying is monitored by different types of regulators, among which neuropeptides play a major role. They are involved in the integration of environmental cues, a...

The common English Channel cuttlefish (Sepia officinalis) reproduces every year on very localized coastal spawning areas after a west–east horizontal migration of several tens of kilometers (80–200 km). The massive arrival of spawners on the coasts of west Cotentin and the Bay of Seine is suspected to be driven by the action of sex pheromones expre...

The avian egg perivitelline layer (PL) is a proteinaceous structure that encloses the egg yolk. It consists of the inner and the outer perivitelline layers (IPL and OPL, respectively) that are assumed to play distinct roles in bird reproduction. To gain insight into their respective function, we analyzed the proteome of IPL and OPL in chicken unfer...

The distribution and functions of neurons in scleractinian corals remain largely unknown. This study focused on the Arg-Phe amide family of neuropeptides (RFamides), which have been shown to be involved in a variety of biological processes in animals, and performed molecular identification and characterization in the adult scleractinian coral Euphy...

Antimicrobial peptides (AMPs) participate in the immune system to avoid infection, are present in all living organisms and can be used as drugs. Fish express numerous AMP families including defensins, cathelicidins, liver-expressed antimicrobial peptides (LEAPs), histone-derived peptides, and piscidins (a fish-specific AMP family). The present stud...

Cuttlefish (Sepia officinalis) haemocytes are potential sources of antimicrobial peptides (AMPs). To study the immune response to Vibrio splendidus and identify new AMPs, an original approach was developed based on a differential transcriptomic study and an in-depth in silico analysis using multiple tools. Two de novo transcriptomes were retrieved...

Cephalopods, like other Protostomes, lack an adaptive immune system and only rely on an innate immune system. The main immune cells are haemocytes, able to respond to pathogens and external attacks. First reports based on morphological observations suggested that the white body located in the optic sinuses of cuttlefish was at the origin of haemocy...

The existence and function of neurons remain largely unexplored in scleractinian corals. To gain a better understanding of neuronal functions in coral physiology, this study focused on Glycine-Leucine-Tryptophan-amide family neuropeptides (GLWamides), which have been shown to induce muscle contraction and larval metamorphosis in other cnidarians. M...

The African bonytongue (Heterotis niloticus) is an excellent candidate for fish farming because it has outstanding biological characteristics and zootechnical performances. However, the absence of sexual dimorphism does not favor its reproduction in captivity or the understanding of its reproductive behavior. Moreover, no molecular data related to...

K4 is a de novo peptide with antibacterial activity on human pathogens. It has a short sequence (14 amino acids), with a cationic N-terminal moiety and an amphipathic ɑ-helix structure. The present paper demonstrates its activity on Vibrio bacteria in a marine environment. It was found non-toxic on marine organisms including Artemia salina, Dicentr...

Chordate gastrin/cholecystokinin (G/CCK) and ecdysozoan sulfakinin (SK) signalling systems represent divergent evolutionary scenarios of a common ancestral signalling system. The present article investigates for the first time the evolution of the CCK/SK signalling system in a member of the Lophotrochozoa, the second clade of protostome animals. We...

No antimicrobial peptide has been identified in cephalopods to date. Annotation of transcriptomes or genomes using basic local alignment Search Tool failed to yield any from sequence identities. Therefore, we searched for antimicrobial sequences in the cuttlefish (Sepia officinalis) database by in silico analysis of a transcriptomic database. Using...

Aquaculture production is expected to double by 2030, and demands for aquafeeds and raw materials are expected to increase accordingly. Sustainable growth of aquaculture will require the development of highly nutritive and functional raw materials to efficiently replace fish meal. Enzymatic hydrolysis of marine and aquaculture raw materials could b...

The cuttlefish (Sepia officinalis) is a cephalopod mollusk distributed on the western European coast, in the West African Ocean and in the Mediterranean Sea. On the Normandy coast (France), cuttlefish is a target species of professional fishermen, so its reproduction strategy is of particular interest in the context of stock management. Egg-laying,...

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...

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Cephalopods exhibit a wide variety of behaviors such as prey capture, communication, camouflage and reproduction, thanks to a complex central nervous system (CNS) divided into several functional lobes that express a wide range of neuropeptides involved in the modulation of behaviors and physiological mechanisms associated with the main stages of th...

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 wit...

The development of aquaculture is related to an increased demand for aquaculture feed. The replacement of fishmeal by by-product hydrolysates from marine animals has become the specialty of SPF DIANA. Low-molecular-weight nitrogenous compounds play a determining role in the feeding behavior of species of interest for aquaculture, but also in nutrit...

Varroa destructor is the main concern related to the gradual decline of honeybees. Nowadays, among the various acaricides used in the control of V. destructor, most presents increasing resistance. An interesting alternative could be the identification of existent molecules as new acaricides with no effect on honeybee health. We have previously cons...

Since the initial characterization of the cardioexcitatory peptide FMRFamide in the bivalve mollusk Macrocallista nimbosa, a great number of FMRFamide-like peptides (FLPs) have been identified in mollusks. FLPs were initially isolated and molecularly characterized in model mollusks using biochemical methods. The development of recombinant technolog...

Sponges and bacteria have lived together in complex consortia for 700 million years. As filter feeders, sponges prey on bacteria. Nevertheless, some bacteria are associated with sponges in symbiotic relationships. To enable this association, sponges and bacteria are likely to have developed molecular communication systems. These may include molecul...

Two novel members of the oxytocin/vasopressin superfamily have been identified in the cephalopod Sepia officinalis. Oxytocin/vasopressin gene sequences were cloned by Race PCR. The two precursors we identified exhibit the classical organization of OT/VP superfamily precursors: a signal peptide followed by a nonapeptide and a neurophysin domain. The...

The cephalopod mollusk Sepia officinalis can be considered as a relevant model for studying reproduction strategies associated to seasonal migrations. Using transcriptomic and peptidomic approaches, we aim to identify peptide sex pheromones that are thought to induce the aggregation of mature cuttlefish in their egg-laying areas. To facilitate the...

Incorporation of aza-β(3)-amino acids into an endogenous neuropeptide from mollusks (ALSGDAFLRF-NH(2)) with weak antimicrobial activity allows the design of new AMPs sequences. Depending on the nature of the substitution, this can render the pseudopeptides inactive or lead to a drastic enhancement of the antimicrobial activity without high cytotoxi...

Gonadotropin-releasing hormone (GnRH), a key neuropeptide regulating reproduction in vertebrates has now been characterized in a number of non-vertebrate species. Despite the demonstration of its ancestral origin, the structure and the function of this family of peptides remain poorly known in species as distant as lophotrochozoans. In this study,...

The K4 peptide (KKKKPLFGLFFGLF) was recently demonstrated to display good antimicrobial activities against various bacterial strains and thus represents a candidate for the treatment of multiple-drug resistant infections. In this study, we use various techniques to study K4 behaviour in different media: water, solutions of detergent micelles, phosp...

Extracellular products (ECPs) of the pathogenic Vibrio aestuarianus 01/32 were previously reported to display lethality in Crassostrea gigas oysters and to cause morphological changes and immunosuppression in oyster hemocytes. To identify the source of this toxicity, biochemical and genetic approaches were developed. ECP protease activity and letha...

Antibacterial peptide fractions generated via proteolytic processing of snow crab by-products exhibited activity against Gram-negative and Gram-positive bacteria. Among the bacterial strains tested, peptide fractions demonstrated inhibitory activity against the Gram-negative bacteria such as Aeromonas caviae, Aeromonas hydrophila, Campylobacter jej...

From a single LC–MS/MS analysis, a new C-terminally extended RFamide neuropeptide was characterized in Sepia officinalis. The experimental strategy was based on the specific neutral loss associated with RFamide breakdown. Mass losses of 17 Da (C-terminally amide) and 320 Da (RFamide) have been observed for three known peaks of m/z 581.7 (FLRFamide)...

Cyclic peptides having a random alternation of L-α-aminoacyl residues and of aza-β3-aminoacyl residues and uses thereof.

With 14 residues organized as two domains linked by a single proline, the de novo peptide called K4 was designed, using Antimicrobial Peptide Database, to exert antibacterial activity. The N-terminal domain is composed of four lysines enhancing membrane interactions, and the C-terminal domain is putatively folded into a hydrophobic alpha-helix. Fol...

Coccolithus braarudii and Calcidiscus leptoporus are 2 coccolithophores (Prymnesio- phyceae: Haptophyta) known to possess a complex heteromorphic life cycle, with alternation between a motile holococcolith-bearing haploid stage and a non-motile heterococcolith-bearing diploid stage. The ecological implications of this type of life cycle in coccolit...

For more than six decades, several studies have shown that genital products to entering the mantle cavity via the incurrent siphon, initiate in oyster, strong and rhythmic contractions of the adductor muscle (AM). In order to characterize the regulatory peptides capable of triggering AM contractions, we focused on the identification of putative myo...

Penaeidins are a family of antimicrobial peptides of 47-63 residues isolated from several species of shrimp. These peptides display a proline-rich domain (N-terminal part) and a cysteine-rich domain (C-terminal part) stabilized by three conserved disulfide bonds whose arrangement has not yet been characterized. The recombinant penaeidin-3a of Litop...

Egg mass extract was used to characterize regulatory peptides, involved in the successive steps of egg-laying of the cuttlefish Sepia officinalis. Among these peptides, a C-terminally amidated hexapeptide revealed a sperm-attracting activity. MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) and Edman degra...

This paper demonstrates for the first time the occurrence of tetrapeptides related to APGWamide in the mollusk cephalopod Sepia officinalis. LC-ESI-MS/MS analysis allowed the identification of the APGWamide-related peptides predicted by the two genes cloned previously in Lymnaea stagnalis and in Mytilus edulis, as well as the dipeptide GWamide rele...

In Sepia officinalis, egg-laying consists of successive stereotyped steps in the following sequence: (1) ovulation, (2) embedding, (3) fertilization, (4) attachment of the egg to a suitable substrate. Study of the cuttlefish in the natural environment, in captivity and in the lab has clarified some of the egg-laying mechanisms. New peptides are ide...

A novel neuropeptide acting as a myosuppressor on esophagus, funnel and mantle muscular fibers has been isolated from the stellar ganglia of the mollusk cephalopod Sepia officinalis by means of HPLC analysis. Fractions were monitored using a myotropic bioassay. After three separation steps, MALDI-TOF spectrum revealed one main peak at m/z 756.6. Th...

In the cuttlefish Sepia officinalis, the successive steps of egg laying are controlled by multiple neuropeptides. Recent experiments led us to suppose that there was possible involvement of a second regulation pathway by the release of ovarian regulatory peptides in the genital tract. Using HPLC fractionation and an in vitro biological test, a C-te...

A novel tetrapeptide modulating the oviduct contractions was characterized from egg mass of Sepia officinalis. After two purification steps by rpHPLC, an apparent pure fraction containing the biological activity was submitted to MALDI-TOF analysis. The mass spectrum revealed 6 peaks of m/z 293, 505, 596, 613, 728, and 745. The tissue peptide mappin...

The APGWamide-related neuropeptides, predicted by the cDNA of the APGWamide precursor of Mytilus edulis, have been sought by means of HPLC and electrospray mass ionization. The three predicted peptides KPGWamide, RPGWamide and TPGWamide were detected in the three main muscles and surprisingly an ion at m/z 429 corresponding to the gastropod peptide...

At the beginning of egg-laying, in the cuttlefish Sepia officinalis, the oocytes accumulated in the proximal oviduct are released into the mantle cavity by the contractions of the oviduct before being encapsulated and fertilised. A bioassay based on the recording of the contractile activity of the distal oviduct was performed to characterise the mo...

The peptidergic control of egg-laying was investigated in Sepia officinalis by using a myotropic bioassay. Three myotropic high-performance liquid chromatography fractions were obtained from optic lobe extracts. In the first fraction, FMRFamide (FMRFa) and FLRFa were isolated and sequenced. FMRFa-related peptides then were sought by dotting immunob...