High-resolution structural and elemental analyses of calcium storage structures synthesized by the noble crayfish Astacus astacus

Abstract : During premolt, crayfish develop deposits of calcium ions, called gastroliths, in their stomach wall. The stored calcium is used for the calcification of parts of the skeleton regularly renewed for allowing growth. Structural and molecular analyses of gastroliths have been primarily performed on three crayfish species, Orconectes virilis, Procambarus clarkii, and more recently, Cherax quadricarinatus. We have performed high-resolution analyses of gastroliths from the native noble crayfish, Astacus astacus, focusing on the microstructure, the mineralogical and elemental composition and distribution in a comparative perspective. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) observations showed a classical layered microstructure composed of 200-nm diameter granules aligned along fibers. These granules are themselves composed of agglomerated nanogranules of 50 nm-mean diameters. Denser regions of bigger fused granules are also present. Micro-Raman spectroscopy show that if A. astacus gastroliths, similarly to the other analyzed gastroliths, are mainly composed of amorphous calcium carbonate (ACC), they are also rich in amorphous calcium phosphate (ACP). The presence of a carotenoid pigment is also observed in A. astacus gastrolith contrary to C. quadricarinatus. Energy-dispersive X-ray spectroscopy (EDX) analyses demonstrate the presence of minor elements such as Mg, Sr, Si and P. The distribution of this last element is particularly heterogeneous. X-ray absorption near edge structure spectroscopy (XANES) reveals an alternation of layers more or less rich in phosphorus evidenced in the mineral phase as well as in the organic matrix in different molecular forms. Putative functions of the different P-comprising molecules are discussed.
Document type :
Journal articles
Complete list of metadatas

Cited literature [98 references]  Display  Hide  Download

https://hal.sorbonne-universite.fr/hal-01373791
Contributor : Gestionnaire Hal-Upmc <>
Submitted on : Thursday, September 29, 2016 - 11:32:03 AM
Last modification on : Wednesday, May 15, 2019 - 3:45:12 AM
Long-term archiving on : Friday, December 30, 2016 - 12:42:49 PM

File

Luquet_High-resolution.pdf
Files produced by the author(s)

Identifiers

Citation

Gilles Luquet, Murielle Salomé, Andreas Ziegler, Céline Paris, Aline Percot, et al.. High-resolution structural and elemental analyses of calcium storage structures synthesized by the noble crayfish Astacus astacus. Journal of Structural Biology, Elsevier, 2016, ⟨10.1016/j.jsb.2016.09.001⟩. ⟨hal-01373791⟩

Share

Metrics

Record views

459

Files downloads

329