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Registros recuperados: 40 | |
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Ky, Chin-long; Demmer, Jonathan; Blay, Carole; Lo, Cedrik. |
Pinctada margaritifera is an economically important marine bivalve species for cultured pearl production in French Polynesian aquaculture. In order to evaluate the influence of donor oyster age on pearl quality traits, experiments were conducted over 6 years using both grafts and surgreffe operations. At harvest, 6 pearl quality traits were recorded and compared: surface defects, luster, grade, darkness level, and visual color. Analyzing the quality traits of pearls harvested in the initial graft process and those of pearls obtained from surgreffe experiments allowed a comparison of the influence of pearl sac cells originating from the initial mantle graft, which aged together with their recipient oysters. The results demonstrated a significant decrease... |
Tipo: Text |
Palavras-chave: Pearl oyster age; Pinctada margaritifera; Surgreffe; Pearl grade; Pearl colour. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00283/39472/37953.pdf |
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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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Stenger, Pierre-louis; Vidal-dupiol, Jeremie; Reisser, Celine; Planes, Serge; Ky, Chin-long. |
The bivalve Pinctada margaritifera has the capacity to produce the most varied and colourful pearls in the world. Colour expression in the inner shell is under combined genetic and environmental control and is correlated with the colour of pearls produced when the same individual is used as a graft donor. One major limitation when studying colour phenotypes is grader subjectivity, which leads to inconsistent colour qualification and quantification. Through the use of HSV (Hue Saturation Value) colour space, we created an R package named ‘ImaginR’ to characterise inner shell colour variations in P. margaritifera. Using a machine-learning protocol with a training dataset, ImaginR was able to reassign individual oysters and pearls to predefined human-based... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00497/60900/64239.pdf |
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Blay, Carole; Planes, Serge; Ky, Chin-long. |
Grafting mantle tissue of a donor pearl oyster into the gonad of a recipient oyster results in the formation of a chimera, the pearl sac. The phenotypic variations of this chimera are hypothesized to be the result of interactions between the donor and recipient genomes. In this study, the heritability of phenotypic variation and its association with gene expression were investigated for the first time during P. margaritifera pearl production. Genetic variance was evaluated at different levels, 1) before the graft operation (expression in graft tissue), 2) after grafting (pearl sac tissue expression in chimera) and 3) on the product of the graft (pearl phenotype traits) based on controlled bi-parental crosses and the F1 generation. Donor related genetic... |
Tipo: Text |
Palavras-chave: Gene expression; Heritability; Pearl oyster; Phenotype; Pinctada margaritifera. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00433/54505/55876.pdf |
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Le Pabic, Lore; Parrad, Sophie; Sham Koua, Manaarii; Nakasai, Seiji; Saulnier, Denis; Devaux, Dominique; Ky, Chin-long. |
Size is the most important and valuable quality of the cultured black-lip pearl, Pinctada margaritifera. As this pearl aquaculture is carried out at numerous grow-out sites, this study analyzes the environmental influence on pearl size parameters (nacre weight and thickness) in relation to the recipient oyster biometric parameters (shell thickness, height, width, and oyster weight) at harvest time. Toward this end, an experimental graft was designed by using a homogeneous donor oyster phenotype. The recipient oysters were randomly and equally transferred and reared in five commercial and contrasting grow-out locations. Overall inter-site comparisons revealed that the cultured pearl size (N=2168) and the biometric parameters of the recipient oysters were... |
Tipo: Text |
Palavras-chave: Pinctada margaritifera; Cultured pearl size; Donor oysters; Recipient oysters; Gene expression; Environmental influences. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00321/43191/42738.pdf |
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Blay, Carole; Planes, Serge; Ky, Chin-long. |
Nucleated pearls are produced by molluscs of the Pinctada genus through the biomineralisation activity of the pearl sac tissue within the recipient oyster. The pearl sac originates from graft tissue taken from the donor oyster mantle and its functioning is crucial in determining key factors that impact pearl quality surface characteristics. The specific role of related gene regulation during gem biogenesis was unknown, so we analysed the expression profiles of eight genes encoding nacreous (PIF, MSI60, PERL1) or prismatic (SHEM5, PRISM, ASP, SHEM9) shell matrix proteins or both (CALC1) in the pearl sac (N = 211) of Pinctada margaritifera during pearl biogenesis. The pearls and pearl sacs analysed were from a uniform experimental graft with sequential... |
Tipo: Text |
Palavras-chave: Biomineralisation; Relative gene expression; Pearl sac; Biomarkers; Pearl quality; Pinctada margaritifera. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00435/54622/56022.pdf |
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Ky, Chin-long; Demmer, Jonathan; Sham-koua, Manaarii; Cabral, Philippe. |
Production of larger, rounder, high-quality cultured pearls with fewer circles is one of the main challenges of Pinctada margaritifera aquaculture faced by every pearl farm in French Polynesia. Although bigger pearl sizes can be achieved through surgreffe operations (implantation of a second nucleus following pearl harvest), control of the development of pearl circles and shapes still remains unclear, as illustrated by grafter’s empirical rules, where often the surgreffe process is only performed after production of uncircled and round pearl shapes. The present study was designed with a real pearl by pearl traceability to reveal for the first time the development of circles and shapes from graft and surgreffe, in relation to the size of the pearl sac. This... |
Tipo: Text |
Palavras-chave: Pearl oyster; Pinctada margaritifera; Surgreffe; Circled pearls; Pearl shapes; Pearl sac. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38690/37187.pdf |
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Blay, Carole; Planes, Serge; Ky, Chin-long. |
Grafting associates two distinct genotypes, each of which maintains its own genetic identity throughout the life of the grafted organism. Grafting technology is well documented in the plant kingdom, but much less so in animals. The pearl oyster, Pinctada margaritifera, produces valuable pearls as a result of the biomineralisation process of a mantle graft from a donor inserted together with a nucleus into the gonad of a recipient oyster. To explore the respective roles of donor and recipient in pearl formation, a uniform experimental graft was designed using donor and recipient oysters monitored for their growth traits. At the same time, phenotypic parameters corresponding to pearl size and quality traits were recorded. Phenotypic interaction analysis... |
Tipo: Text |
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Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00387/49809/50382.pdf |
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Ky, Chin-long; Broustal, Floriane; Koua, Manaarii Sham; Quillien, Virgile; Beliaeff, Benoit. |
Understanding the respective roles played by donor and recipient pearl oysters in pearl quality determination in relation to the environment is a challenge for the pearl industry. In most Pinctada species, pearl size is mainly related to recipient oyster growth performance, but also relies to some extent on the biomineralisation activity of the pearl sac, a tissue that originates from the donor oyster mantle. We examined donor effect on pearl size in response to culture in the lagoons on Arutua and Apataki atolls. Overall nacre weight and thickness were greater in Arutua than in Apataki, but sensitivity to the environment differed between donors. Some donors were associated with significantly heavier and thicker nacre in Arutua (I group), while others had... |
Tipo: Text |
Palavras-chave: Biomineralisation; Environment; Pearl oyster; Pearl size; Pinctada margaritifera. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00425/53699/54610.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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Stenger, Pierre-louis; Ky, Chin-long; Reisser, Celine; Cosseau, Céline; Grunau, Christoph; Mege, Mickael; Planes, Serge; Vidal-dupiol, Jeremie. |
Today, it is common knowledge that environmental factors can change the color of many animals. Studies have shown that the molecular mechanisms underlying such modifications could involve epigenetic factors. Since 2013, the pearl oyster Pinctada margaritifera var. cumingii has become a biological model for questions on color expression and variation in Mollusca. A previous study reported color plasticity in response to water depth variation, specifically a general darkening of the nacre color at greater depth. However, the molecular mechanisms behind this plasticity are still unknown. In this paper, we investigate the possible implication of epigenetic factors controlling shell color variation through a depth variation experiment associated with a DNA... |
Tipo: Text |
Palavras-chave: Pearl oyster; Environmental pressure; Depth; Color change; Pigmentation; DNA methylation; Methylome characterization. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00685/79667/82436.pdf |
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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 |
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Ky, Chin-long; Blay, Carole; Sham-koua, Manaarii; Vanaa, Vincent; Lo, Cedrik; Cabral, Philippe. |
Individual Pinctada margaritifera molluscs were collected from the Takapoto atoll (Tuamotu Archipelago, French Polynesia) and used to produce ten first generation full-sib families in a hatchery system, following artificial breeding protocols. After three years of culture, these progenies were transferred to Rangiroa atoll (Tuamotu Archipelago, French Polynesia) and tested for their potential as graft donors. A large-scale grafting experiment of 1500 grafts was conducted, in which a single professional grafter used ten individual donor oysters from each of the ten families, grafting 15 recipient oysters from each donor. The recipient oysters were all obtained from wild spat collection in Ahe (Tuamotu Archipelago, French Polynesia). After 18 months of... |
Tipo: Text |
Palavras-chave: Cultured pearl oyster; Pearl quality; Progeny effects; Heritability; Genetic selection; Pinctada margaritifera; French Polynesia. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00152/26310/24380.pdf |
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Ky, Chin-long; Barre, Philippe; Noirot, Michel. |
The objective of the paper was to identify the number of major loci explaining caffeine content in coffee seeds. Investigations were based on previously published results: (1) Caffeine binds to chlorogenic acids in a 1:1 molecular ratio; (2) Between species, the caffeine content is correlated to the chlorogenic acid content; (3) Only a part of chlorogenic acids is bound to caffeine. Especially, the content ratio between caffeine and chlorogenic acids varied between species. For identifying the number of major loci, a quantitative trait locus (QTL) approach was carried out using an interspecific cross between two highly differentiated species-Coffea liberica dewevrei and Coffea pseudozanguebariae, the latter being a caffeine-free species. As main finding,... |
Tipo: Text |
Palavras-chave: Coffea; Chlorogenic acids; Caffeine; QTL; Interspecific cross. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00152/26298/24429.pdf |
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Ky, Chin-long; Lau, Christophe; Sham Koua, Manaarii; Lo, Cedrik. |
The black-lipped pearl oyster Pinctada margaritifera is of high economic importance in French Polynesia. Arecent decline in pearl value led to the initiation of several genetic breeding programs aiming to improve production traits, including oyster shell growth, which dictates the time of grafting, size of the implanted nuclei, and biomineralization capacities. We assessed shell diameters on hatchery-produced spat to analyze juvenile growth performance of four half-sib families derived from polyandry (one dam crossed with two sires) and polygyny (two dams crossed with one sire) using gametes obtained by thermal shock or gonad scarification. Spat growth was monitored over 3 mo, with shell diameter measured weekly. Results revealed that the spawning method... |
Tipo: Text |
Palavras-chave: Pearl oysters; Pinctada margaritifera; Juvenile; Growth performance; Spawning procedure. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00310/42167/41470.pdf |
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Ky, Chin-long; Sham Koua, Manaarii; Le Moullac, Gilles. |
Beaded cultured pearl farming is a lengthy aquaculture process, particularly when the pearl oysters are produced through a hatchery propagation system, and includes the key steps of artificial breeding, larval and spat rearing before graft operations can take place. Within its genus, Pinctada margaritifera has the ability to produce the widest range of pearl colours, thanks to the donor colour polymorphism of the inner shell, which is mainly responsible for colour transmission. As hatchery spat production in P. margaritifera leads to several colour phenotypes (at 3 months old), the aim of this study was to determine whether a relation exists between the colour of the donors as spat and the final pearl colour. In the experiment, which took place over a... |
Tipo: Text |
Palavras-chave: Pinctada margaritifera; Phenotypes; Spat shell colour; Earlier selection; Pearl colour. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00418/52969/53895.pdf |
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Ky, Chin-long; Blay, Carole; Sham-koua, Manaarii; Lo, Cédrik; Cabral, Philippe. |
The top aquaculture species in French Polynesia is Pinctada margaritifera, a mollusc grown for the production of a unique gem: the black pearl. One of the challenges facing the pearl farming industry is to "produce less but better pearls" through genetic improvement. An experimental hatchery system was used to generate full-sib families to be tested for their potential as donor "oysters". A large-scale grafting experiments was done and seven cultured pearl quality traits: grade, surface defects, lustre, darkness level, visual colour categories, circles and shape categories were recorded. Our results revealed, for the first time, significant phenotypic relationships between these quality traits. The grade A cultured pearl class had the largest proportion of... |
Tipo: Text |
Palavras-chave: Pearl "oyster"; Pinctada margaritifera; Donor "oyster"; Cultured pearl quality; Pearl grade; Pearl colour; Pearl shape; Selective breeding. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00190/30130/28592.pdf |
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Ky, Chin-long; Nakasai, Seiji; Molinari, Nicolas; Devaux, Dominique. |
Cultured pearls quality produced by the mollusc Pinctada margaritifera var. cumingi is determined by a panel of criteria, of which shape is one of the most relevant. Cultured pearls with round and semi-round (RS) shapes are the most valuable. Decreasing the proportion of other pearl shapes (OT: baroque, button, drop, oval), and especially the circled pearls (CL) and rejects (rebuts: RT), is an important challenge for the pearl industry. The present study examined the effect of grafter skill and season of graft on the variation in proportions of CL, RS, OT and RT cultured pearl shape categories in a mono-site culture (Mangareva island lagoon). Six large-scale grafting experiments, carried out in the same way as commercial grafting sessions, were made by... |
Tipo: Text |
Palavras-chave: Pinctada margaritifera; Cultured pearl; Grafter skill; Pearl shapes; Circled pearls; Grafting season. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00216/32745/31150.pdf |
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Le Moullac, Gilles; Schuck, Lucie; Chabrier, Sebastien; Belliard, Corinne; Lyonnard, Pierre; Broustal, Floriane; Soyez, Claude; Saulnier, Denis; Brahmi, Chloe; Ky, Chin-long; Beliaeff, Benoit. |
The objective of this study was to observe the impact of temperature on pearl formation using an integrative approach describing the rotation of the pearls, the rate of nacre deposition, the thickness of the aragonite tablets and the biomineralizing potential of the pearl sac tissue though the expression level of some key genes. Fifty pearl oysters were grafted with magnetized nuclei to allow the rotation of the pearls to be described. Four months later, 32 of these pearl oysters were exposed to four temperatures (22, 26, 30 and 34°C) for 2 weeks. Results showed that the rotation speed differed according to the movement direction: pearls with axial movement (AM) had a significantly higher rotation speed than those with random movement (RM). Pearl... |
Tipo: Text |
Palavras-chave: Magnetometer; Rotation speed; Nacre growth; Nacre thickness; Gene expression; Pmarg-Pif177. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00450/56196/57753.pdf |
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Registros recuperados: 40 | |
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