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| Registros recuperados: 20 | |
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| Gueguen, Yannick; Montagnani, Caroline; Joubert, Caroline; Marie, Benjamin; Belliard, Corinne; Tayale, Alexandre; Fievet, Julie; Levy, Peva; Piquemal, David; Marin, Frederic; Le Moullac, Gilles; Ky, Chin-long; Garen, Pierre; Lo, Cedrick; Saulnier, Denis. |
| Tahiti’s pearl farming industry plays a major socio-economic role in French Polynesia. In an increasingly competitive market where the production of high quality pearls becomes essential, research can help secure and ensure sustainable production. In that context, Ifremer, in close collaboration with the “direction des resources marines” (French Polynesian government agency) has developed research projects on the “sustainable development of pearl farming”. This program is organized along 3 axes: (1) understanding the animal physiology and initiating a genetically selective breeding program of donor oysters; (2) understanding pearl oyster larvae dispersal and recruitment; (3) understanding the molecular mechanisms underlying biomineralization processes... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Biomineralization; Pinctada margaritifera. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00167/27840/26049.pdf |
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| Marie, Benjamin; Joubert, Caroline; Belliard, Corinne; Tayale, Alexandre; Zanella-cleon, Isabelle; Marin, Frederic; Gueguen, Yannick; Montagnani, Caroline. |
| Nacre of the Pinctada pearl oyster shells is composed of 98% CaCO3 and 2% organic matrix. The relationship between the organic matrix and the mechanism of nacre formation currently constitutes the main focus regarding the biomineralization process. In this study, we isolated a new nacre matrix protein in P. margaritifera and P. maxima, we called Pmarg- and Pmax-MRNP34 (methionine-rich nacre protein). MRNP34 is a secreted hydrophobic protein, which is remarkably rich in methionine, and which is specifically localised in mineralizing the epithelium cells of the mantle and in the nacre matrix. The structure of this protein is drastically different from those of the other nacre proteins already described. This unusual methionine-rich protein is a new member in... |
| Tipo: Text |
Palavras-chave: Matrix protein; Methionine-rich; Biomineralization; Mollusc; Nacre; Calcifying mantle. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00077/18870/16645.pdf |
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| Latchere, Oihana; Fievet, Julie; Lo, Cedrik; Schneider, Denis; Dieu, Stephanie; Cabral, Philippe; Belliard, Corinne; Ky, Chin-long; Gueguen, Yannick; Saulnier, Denis. |
| The present study investigated the effect of electrolysis on the biomineralization capacities of juveniles of the mollusk Pinctada margaritifera for the first time. Size-selected individuals from two groups, “Medium” and “Large”, from a multi-parental family produced in a hatchery system were subjected to electrolysis under a low voltage current over a nine-week experimental period. The growth of the juveniles was individually monitored and assessed weekly by wet weight and shell height measurements. At the end of the experiment, mantle tissue was sampled for biomineralization-related gene expression analysis. Electrolysis significantly increased pearl oyster growth in terms of shell height and wet weight for Large juveniles from the 5th and the 2nd week,... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Pinctada margaritifera; Electrolysis; Biomineralization; Gene expression. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00343/45410/44924.pdf |
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| Papini,S.; Andréa,M. M.. |
| Enhanced degradation of the fungicide metalaxyl was investigated in two soils: a gley humic (GH) and a Dark Red Latosol (LE), collected at sites never exposed to the fungicide. The soil samples were treated with successive applications of metalaxyl as a commercial formulation and 14C-metalaxyl in laboratory. Metalaxyl biodegradation was analyzed during 63 days by means of radiometric techniques to verify biomineralization and degradation product formation from the applied 14C-metalaxyl. Although biomineralization (maximum of 14 and 8% in the GH and LE soils, respectively), and partial degradation (about 32 and 48%, respectively) were detected in both soils, enhanced degradation was verified only in the GH soil. Results proved that metalaxyl behaves... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Degradation; Fungicide; Biomineralization. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832000000200023 |
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| Cuif, Jean-pierre; Burghammer, Manfred; Chamard, Virginie; Dauphin, Yannicke; Godard, Pierre; Le Moullac, Gilles; Nehrke, Gernot; Perez-huerta, Alberto. |
| Consistently classified among the references for calcite simple prisms, the microstructural units that form the outer layer of the Pinctada margaritifera have been investigated through a series of morphological, crystallographical and biochemical characterizations. It is often said that the polygonal transverse shape of the prisms result from the competition for space between adjacent crystals. In contrast to this classical scheme the Pinctada prisms appear to be composed of four successive developmental stages from the concentrically growing disks on the internal side of the periostracum to the morphological, structural and compositional changes in both envelopes and mineral components at the end of the prisms. These latest structural and compositional... |
| Tipo: Text |
Palavras-chave: Biomineralization; Bivalve shell; Microstructure; Calcite prisms. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00249/36039/34574.pdf |
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| Lemer, Sarah; Saulnier, Denis; Gueguen, Yannick; Planes, Serge. |
| Background: Color polymorphism in the nacre of pteriomorphian bivalves is of great interest for the pearl culture industry. The nacreous layer of the Polynesian black-lipped pearl oyster Pinctada margaritifera exhibits a large array of color variation among individuals including reflections of blue, green, yellow and pink in all possible gradients. Although the heritability of nacre color variation patterns has been demonstrated by experimental crossing, little is known about the genes involved in these patterns. In this study, we identify a set of genes differentially expressed among extreme color phenotypes of P. margaritifera using a suppressive and subtractive hybridization (SSH) method comparing black phenotypes with full and half albino individuals.... |
| Tipo: Text |
Palavras-chave: Differential expression; Biomineralization; Nacre; Pearl; Pigmentation; Albino. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38627/37167.pdf |
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| Le Moullac, Gilles; Soyez, Claude; Vidal-dupiol, Jeremie; Belliard, Corinne; Fievet, Julie; Sham-koua, Manaarii; Lo-yat, Alain; Saulnier, Denis; Gaertner-mazouni, N.; Gueguen, Yannick. |
| The possible consequences of acidification on pearl farming are disruption of oyster metabolism and change in growth. In the laboratory, we studied the impact of pCO2 (3540, 1338 and 541μatm) on the physiology of pearl oysters exposed for 100 days. This experiment was repeated after an interval of one year. Several physiological compartments were examined in pearl oysters: the scope for growth by measuring ingestion, assimilation and oxygen consumption, gametogenesis by means of histological observations, shell growth by measurement and observation by optical and electronic microscopy, and at molecular level by measuring the expression of nine genes of mantle cells implied in the biomineralisation process. Results from both experiments showed that high... |
| Tipo: Text |
Palavras-chave: Global change; Pearl oyster; Bioenergetic; Biomineralization; Pacific Ocean; French Polynesia. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00321/43189/42737.pdf |
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| Trinkler, Nolwenn; Bardeau, Jean-francois; Marin, Frederic; Labonne, Maylis; Jolivet, Aurelie; Crassous, Philippe; Paillard, Christine. |
| The mineral phase of shell repair in the Manila clam Venerupis philippinarum affected by brown ring disease (BRD) was characterised at various scales and at various stages of shell repair by confocal Raman microspectrometry and scanning electron microscopy. Spherulitic and quadrangular aragonite microstructures associated with polyene pigments were clearly observed. Von Kossa staining showed that at the beginning of shell repair, hemocytes are filled with insoluble calcium carbonate salts in all fluids and then are transported toward the extrapallial fluids and the repair sites. Our analyses suggest that after a Vibrio tapetis attack and BRD deposit some clams rapidly cover the deposit, resulting in a modification in the microstructure, which could be... |
| Tipo: Text |
Palavras-chave: Aragonite; Hemocytes; Shell microstructure; Calcium carbonate; Biomineralization; Mollusc; Raman microspectrometry; Scanning electron microscopy. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14065/11301.pdf |
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| Arnaud, Sophie; Goyard, Emmanuel; Vonau, Vincent; Herbaut, C; Prou, Jean; Saulnier, Denis. |
| Most bivalves species of the genus Pinctada are well known throughout the world for production of white or black pearls of high commercial value. For cultured pearl production, a mantle allograft from a donor is implanted into the gonad of a recipient oyster, together with a small inorganic bead. Because of the dedifferentiation of cells during the first steps of the host oyster's immunological reaction, so far the fate of the graft and its exact role in the process of pearl formation could not be determined via classical histological methods. Here we report the first molecular evidence of the resilience of the graft in the recipient organism by showing that cells containing genome from the donor are still present at the end of pearl formation. These... |
| Tipo: Text |
Palavras-chave: Genotype; Pearl; Pearl sac; Grafting; Biomineralization; Pearl oyster. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2456.pdf |
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| Le Moullac, Gilles; Soyez, Claude; Latchere, Oihana; Vidal-dupiol, Jeremie; Fremery, Juliette; Saulnier, Denis; Lo Yat, Alain; Belliard, Corinne; Mazouni-gaertner, Nabila; Gueguen, Yannick. |
| The pearl culture is one of the most lucrative aquacultures worldwide. In many South Pacific areas, it depends on the exploitation of the pearl oyster Pinctada margaritifera and relies entirely on the environmental conditions encountered in the lagoon. In this context, assessing the impact of climatic stressors, such as global warming and ocean acidification, on the functionality of the resource in terms of renewal and exploitation is fundamental. In this study, we experimentally addressed the impact of temperature (22, 26, 30 and 34 °C) and partial pressure of carbon dioxide pCO2 (294, 763 and 2485 μatm) on the biomineralization and metabolic capabilities of pearl oysters. While the energy metabolism was strongly dependent on temperature, results showed... |
| Tipo: Text |
Palavras-chave: Global change; Pearl oyster; Bioenergetic; Biomineralization; Pacific ocean; French Polynesia. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00332/44364/43969.pdf |
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| Fleury, C; Marin, F; Marie, B; Luquet, G; Thomas, J; Josse, C; Serpentini, A; Lebel, J. |
| In the present paper, juvenile and adult shells of the green ormer Haliotis tuberculata ('Oreille de Saint-Pierre') were perforated in a zone close to the shell edge and the shell repair process was followed at two levels: (1) by observing the histology of the calcifying mantle in the repair zone and (2) by analyzing with SEM the microstructure of the shell repair zone. Histological data clearly show the presence of calcium carbonate granules into the connective tissues, but not in the epithelial cells. This suggests that calcium carbonate granules are synthesized by sub-epithelial cells and actively transported through the epithelium to the repair zone, via a process which may be similar to that described by Mount et al. [Mount, A.S., Wheeler, A.P.,... |
| Tipo: Text |
Palavras-chave: Microstructure; Mantle epithelium; Biomineralization; Calcium carbonate; Shell repair; Gastropod. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/2008/publication-4377.pdf |
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| Chaparro-Acuña,Sandra Patricia; Becerra-Jiménez,Mónica Liliana; Martínez-Zambrano,José Jobanny; Rojas-Sarmiento,Hugo Alfonso. |
| Abstract Bacteria with ureasic activity are microorganisms found in soil that in presence of urea and calcium, they can produce calcium carbonate, a process known as microbiologically induced calcium carbonate precipitation (MICP). This article discusses this process and its mechanism, as well as bacterial urease, calcium carbonate crystals formed, and factors that affect the efficiency of MICP, as type of bacteria, bacterial cell concentrations, pH, temperature and calcium and urea concentrations. In addition, applications as removal of heavy metals in water, bioconsolidation, biocement and CO2 sequestration are also discussed. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biomineralization; Bacillus; Urease; Carbonates; Heavy metals; Bioconsolidation; Biocementation. |
| Ano: 2018 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-28122018000200277 |
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| Auffret, Pauline; Le Luyer, Jeremy; Sham Koua, Manaarii; Quillien, Virgile; Ky, Chin-long. |
| Background Albino mutations are commonly observed in the animal kingdom, including in bivalves. In the black-lipped pearl oyster Pinctada margaritifera, albino specimens are characterized by total or partial absence of colouration resulting in typical white shell phenotype expression. The relationship of shell colour with resulting cultured pearl colour is of great economic interest in P. margaritifera, on which a pearl industry is based. Hence, the albino phenotype provides a useful way to examine the molecular mechanisms underlying pigmentation. Results Whole transcriptome RNA-sequencing analysis comparing albino and black wild-type phenotypes at three stages over the culture cycle of P. margaritifera revealed a total of 1606, 798 and 187 differentially... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; Albinism; Pigmentation; RNA-seq; Notch signaling pathway; Tyrosinase; Biomineralization. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76420/77477.pdf |
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| Le Luyer, Jeremy; Auffret, Pauline; Quillien, Virgile; Leclerc, Nicolas; Reisser, Celine; Vidal-dupiol, Jeremie; Ky, Chin-long. |
| Background Cultured pearls are unique gems produced by living organisms, mainly molluscs of the Pinctada genus, through the biomineralization properties of pearl sac tissue. Improvement of P. margaritifera pearl quality is one of the biggest challenges that Polynesian research has faced to date. To achieve this goal, a better understanding of the complex mechanisms related to nacre and pearl formation is essential and can now be approached through the use of massive parallel sequencing technologies. The aim of this study was to use RNA-seq to compare whole transcriptome expression of pearl sacs that had producing pearls with high and low quality. For this purpose, a comprehensive reference transcriptome of P. margaritifera was built based on... |
| Tipo: Text |
Palavras-chave: Pinctada margaritifera; Biomineralization; Pearl quality; Pearl sac; RNA-seq. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00475/58695/61207.pdf |
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| Gueguen, Yannick; Czorlich, Yann; Mastail, Max; Le Tohic, Bruno; Defay, Didier; Lyonnard, Pierre; Marigliano, Damien; Gauthier, Jean-pierre; Bari, Hubert; Lo, Cedrik; Chabrier, Sebastien; Le Moullac, Gilles. |
| Cultured pearls are human creations formed by inserting a nucleus and a small piece of mantle tissue into a living shelled mollusc, usually a pearl oyster. Although many pearl observations intuitively suggest a possible rotation of the nucleated pearl inside the oyster, no experimental demonstration of such a movement has ever been done. This can be explained by the difficulty of observation of such a phenomenon in the tissues of a living animal. To investigate this question of pearl rotation, a magnetometer system was specifically engineered to register magnetic field variations with magnetic sensors from movements of a magnetic nucleus inserted in the pearl oyster. We demonstrated that a continuous movement of the nucleus inside the oyster starts after a... |
| Tipo: Text |
Palavras-chave: Pearl oyster; Pearl rotation; Biomineralization. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00275/38598/37127.pdf |
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| Registros recuperados: 20 | |
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