Consulta: subjectFacets:"Nacre"
Registros recuperados: 4
Data/hora: 01/06/2024 18:08:17

Evidence of donor effect on cultured pearl quality from a duplicated grafting experiment on Pinctada margaritifera using wild donors
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Tayale, Alexandre; Gueguen, Yannick; Treguier, Cathy; Le Grand, Jacqueline; Cochennec-laureau, Nathalie; Montagnani, Caroline; Ky, Chin-long.
Producing high quality cultured black pearls from Pinctada margaritifera is one of the major challenges for the "pearl oyster" industry in French Polynesia. In order to assess donor effect on cultured pearl quality, wild Pinctada margaritifera originating from the Tuamotu Archipelago were used in a duplicated grafting experiment. After 12 months of culture, nucleus retention was assessed and seven pearl quality traits recorded on the 454 cultured pearls harvested from the experiment. The traits scored were nacre thickness and pearl weight, surface defects, lustre, grade, and the colour components: 1) darkness of cultured pearl colour, and 2) visual perception of colour class (bodycolor and/or overtone). Our results demonstrate for the first time that...
Tipo: Text
Palavras-chave: Cultured pearl oyster; Pearl quality; Nacre; Donor mollusc; Genetic selection; Pteriidae; Blacklip pearl oyster; Pinctada margaritifera; French Polynesia.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00116/22757/20541.pdf

Identification of genes associated with shell color in the black-lipped pearl oyster, Pinctada margaritifera
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Characterization of MRNP34, a novel methionine-rich nacre protein from the pearl oysters
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Experimental alteration of the &lt;i&gt;Nautilus&lt;/i&gt; shell by factors involved in diagenesis and metamorphism. Part I. Thermal changes in conchiolin matrix of mother-of-pearl
Provedor de dados: Open Marine Archive
Autores: Grégoire, Ch.
1. This paper is an electron microscope study of the alterations produced by temperatures in range of 100°C to 900°C in mother-of-pearl of the modern &lt;i&gt;Nautilus&lt;/i&gt; shell. 2. Fragments of nacreous layers of the shell wall in the living chamber were exposed for 5 minutes to 21 days to dry heat in open vessels and in quartz tubes sealed under vacuum or argon. Other fragments were boiled in sea mud and sea water. 3. In open vessels and in sealed tubes, conversion of aragonite into calcite took place in the samples heated at 400 °C and above. In the 600 °C-900 °C samples, calcite was mixed with varying amounts of calcium oxide. With elevation of temperature, the original hard, compact and stratified mother-of-pearl became progressively brittle,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diagenesis; Metamorphism; Nacre; Nautilus.
Ano: 1968
URL: http://www.vliz.be/imisdocs/publications/294745.pdf