Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The pearl oyster Pinctada margaritifera has the specific ability to produce pearls with the widest range of coloursamong all pearl oyster species. This pearl colour diversity originates from the mantle biomineralising tissue(graft) of the donor oyster, which is originally responsible for the variety of colours of the inner shell surface.This study aimed to: 1) assess the geographic distribution and establish a first stocklist of the colourful oysterphenotypes used as donors in French Polynesia, and 2) investigate the phenotypic relation between inner shellcolouration and the corresponding colour of harvested pearls. With the support of a pearl farmers' network,we investigated the different donor phenotype frequencies among five collection sites (Ahe, Apataki, Takaroa,TakumeandMangareva). This donor evaluation was made during grafting of pearl oysters (N=49,938) obtainedfrom collector stations. Results showed that pearl production is mainly based on six common colourful donorphenotypes classified as monochromatic and polychromatic profiles, which shown different frequenciesamong the collection sites. Experimental grafts (N=4640)were then realised and subsequent culture conductedat a single site in order to avoid pearl colour variation due to environmental influences. Traceability between donors(N=232) and pearls (N=2776), revealed that: 1) yellow (gold) and aubergine (reddish) pearls could bemostly obtained by using the monochromatic yellowand red donor phenotypes, respectively, and 2) one third toone quarter of grey pearlswas inevitably harvested, whatever the polychromatic phenotype chosen as the donor,which leaves at least half the harvest composed of the attractive green and peacock colours. This preliminarystocklist of colour range together with analysis of the colour phenotype transmission between inner shell andpearl provide the basis for producing multiple pearl oyster “colour lines” through hatchery propagation andwould be helpful for future selective breeding programs.Statement of relevance: Donor shell colour selection predict colours of pearls
ISSN: 0044-8486

hal-01489153
https://hal-univ-perp.archives-ouvertes.fr/hal-01489153
DOI : 10.1016/j.aquaculture.2016.10.017

Résumé : 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 during shell and pearl formation. It is in this frame that we have developed a highthroughput Expressed Sequence Tags pyrosequencing program on the calcifying mantle, combined with proteomic analyses of the shell and pearl. We analyzed 276738 EST sequences, leading to the constitution of a P. margaritifera mantle transcripts catalogue of 82 sequences potentially involved in biomineralization. Our results provided direct evidence that our ESTs data set covers a large number of the matrix proteins of P. margaritifera. In addition, our proteomic analysis enabled us to retrieve, in silico, all the sequences from P. margaritifera involved in the biomineralization process already published on databases. Integration of these two methods allowed, for the first time, the global composition of calcifying tissue and calcified structures to be examined in tandem.
Recent Advances in Pearl Research—Proceedings of the International Symposium on Pearl Research 2011.Edited by Shugo Watabe, Kaoru Maeyama and Hiromichi Nagasawa. 2013. ISBN : 978-4-88704-158-5. pp.184-194

Droits : 2013 TERRAPUB. All rights reserved.
http://archimer.ifremer.fr/doc/00167/27840/26049.pdf
http://archimer.ifremer.fr/doc/00167/27840/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The pearl oyster Pinctada margaritifera has the specific ability to produce pearls with the widest range of coloursamong all pearl oyster species. This pearl colour diversity originates from the mantle biomineralising tissue(graft) of the donor oyster, which is originally responsible for the variety of colours of the inner shell surface.This study aimed to: 1) assess the geographic distribution and establish a first stocklist of the colourful oysterphenotypes used as donors in French Polynesia, and 2) investigate the phenotypic relation between inner shellcolouration and the corresponding colour of harvested pearls. With the support of a pearl farmers' network,we investigated the different donor phenotype frequencies among five collection sites (Ahe, Apataki, Takaroa,TakumeandMangareva).Thisdonorevaluationwasmadeduringgraftingofpearloysters(N=49,938)obtainedfrom collector stations. Results showed that pearl production is mainly based on six common colourful donorphenotypes classified as monochromatic and polychromatic profiles, which shown different frequenciesamongthecollectionsites.Experimentalgrafts(N=4640)werethenrealisedandsubsequentcultureconductedat a single site in order to avoidpearl colour variation due to environmental influences. Traceability between do-nors (N = 232) and pearls (N = 2776), revealed that: 1) yellow (gold) and aubergine (reddish) pearls could bemostlyobtainedbyusingthemonochromaticyellowandreddonor phenotypes,respectively,and2)onethirdtoonequarterofgreypearlswasinevitablyharvested,whateverthepolychromaticphenotypechosenasthedonor,which leaves at least half the harvest composed of the attractive green and peacock colours. This preliminarystocklist of colour range together with analysis of the colour phenotype transmission between inner shell andpearl provide the basis for producing multiple pearl oyster “colour lines” through hatchery propagation andwould be helpful for future selective breeding programs.Statement of relevance: Donor shell colour selection predict colours of pearls
ISSN: 0044-8486

hal-01489247
https://hal-univ-perp.archives-ouvertes.fr/hal-01489247
DOI : 10.1016/j.aquaculture.2016.10.017