Shell layers of the black-lip pearl oyster Pinctada margaritifera : matching microstructure and composition

B. Farre (1) , A. Brunelle (2) , O. Laprévote (2) , J.P. Cuif (1) , C.T. Williams (3) , Y. Dauphin (1)

1 IDES - Interactions et dynamique des environnements de surface
2 ICSN - Institut de Chimie des Substances Naturelles
3 Dpt of Mineral & Palaeontology

The nacre prism transition of the mollusc shell Pinctada margaritifera was studied using scanning electron microscopy, electron probe micro-analysis (EPMA) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Mineralogical change is correlated with a change in organic matrix. Previous analyses had shown that sugars were involved in the transition layer (fibrous aragonite). The new Energy Dispersive Spectrometry (EDS) and TOF-SIMS maps show that the modifications at the layer boundary are complex, and that proteins and lipids are also involved. Detailed TOF-SIMS maps show that the thick organic envelopes surrounding the prisms, and between the prisms and the fibrous aragonitic layer, are not composed by regular layers, but are a patchwork of various molecules. The amino acid compositions of the nacreous and prismatic layer are compared thanks to the TOF-SIMS localized analyses. (C) 2011 Elsevier Inc. All rights reserved.

Domaines: Sciences de la Terre; Chimie organique

B. Farre, A. Brunelle, O. Laprévote, J.P. Cuif, C.T. Williams, et al.. Shell layers of the black-lip pearl oyster Pinctada margaritifera : matching microstructure and composition. Comparative Biochemistry and Physiology - Part B: Biochemistry and Molecular Biology, 2011, 159 ((3):), pp.131-139. ⟨10.1016/j.cbpb.2011.03.001⟩. ⟨hal-00599661⟩