Influence of Temperature and Pearl Rotation on Biomineralization in the Pearl Oyster Pinctada margaritifera
|Author(s)||Le Moullac Gilles1, Schuck Lucie1, Chabrier Sebastien2, Belliard Corinne1, Lyonnard Pierre1, Broustal Floriane1, Soyez Claude1, Saulnier Denis1, Brahmi Chloe3, Ky Chin-Long1, Beliaeff Benoit1|
|Affiliation(s)||1 : Ifremer, UMR EIO 241, Labex Corail, Ctr Pacifique, BP 49, F-98719 Tahiti, French Polynesi, France.
2 : Univ Polynesie Francaise, Lab GEPASUD, BP 6570, F-98702 Faaa, French Polynesi, Fr Polynesia.
3 : Univ Polynesie Francaise, UMR EIO 241, Labex Corail, BP 6570, F-98702 Faaa, French Polynesi, Fr Polynesia.
|Source||Journal Of Experimental Biology (0022-0949) (Company Biologists Ltd), 2018-09 , Vol. 221 , N. 18 , P. jeb186858 (7p.)|
|WOS© Times Cited||10|
|Keyword(s)||Magnetometer, Rotation speed, Nacre growth, Nacre thickness, Gene expression, Pmarg-Pif177|
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 growth rate was influenced by temperature, with a maximum between 26 and 30°C but almost no growth at 34°C. Lastly, among the nine genes implicated in the biomineralization process, the Pmarg-Pif177 expression was significantly modified by temperature. These results showed that the rotation speed of the pearls was not linked to pearl growth or to the expression profiles of biomineralizing genes targeted in this study. On the basis of our results, we consider that pearl rotation is a more complex process than formerly thought. Mechanisms involved could include a strong environmental forcing in immediate proximity to the pearl. Another implication of our findings is that, in the context of ocean warming, pearl growth and quality can be expected to decrease in pearl oysters exposed to temperatures above 30°C.