Effect of electrolysis treatment on the biomineralization capacities of pearl oyster Pinctada margaritifera juveniles

Abstract

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, respectively, until the end of the experiment. However, differences were only significant for Medium individuals from the 7th week for shell height and from the 9th week for wet weight. Furthermore, transcriptional analysis of six known biomineralization genes coding for shell matrix proteins of calcitic prisms and/or nacreous shell structures revealed that five were significantly overexpressed in the mantle mineralizing tissue under electrolysis: three in common between the two size class groups and two that were expressed exclusively in one or the other group. Finally, we found no statistical difference of the shell thickness ratio between individuals undergoing electrolysis and control conditions. Taken together, our results indicate, for the first time in a calcifying marine organism, that electrolysis influences molecular mechanisms involved in biomineralization and may stimulate some parameters of pearl oyster growth rate. Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

Integrated management of pearl culture in French Polynesia in the context of global change: Synopsis of existing results

“…The project designed provided close links between pure-science approaches, including the ecophysiology and genetic diversity of the species (Le Moullac et al 2016a,b ;Blay et al 2016), the interaction of pearl culture with the environment (Lacoste and Mazouni, 2016 ;Le Moullac et al (2016a) and Blay et al 2016), the strategies of businesses with regard to the proposed innovations (Latchere et al 2016 ;Bertucci et al 2016) and risk management, and, finally, the collaborative construction of indicators for monitoring the industry (Rey-Valette et al 2015). In this context, the resultst of the research will contribute to the development of new technologies, strategies, tools and incentives for managing transitions and adaptations of Polynesian pearl culture in the context of global change.Another innovative aspect of the project was to bring together a very wide variety of disciplines which has combined their broad range of skills to answer questions on sustainable and integrated management of pearl culture in French Polynesia.…”

“…Hence, in the frame of that project, we have obtained a precise evaluation of the current status of P. margaritifera genetic diversity in French Polynesia, an understanding of the relationship between pearl oyster recruitment and environmental conditions and a "model tool" to predict larval recruitment in the Ahe atoll (Andrefouet et al, 2016 ;Thomas et al, 2016). In addition, improved husbandry and grafting practices (Latchere et al, 2016) and designing breeding objectives for the genetic improvement of P.…”