Search results for "Nautilus macromphalus"
showing 3 items of 3 documents
Nacre evolution: a proteomic approach.
2009
AbstractFrom an evolutionary viewpoint, the molluscan nacre constitutes a fascinating object. This microstructure appeared early, in the Lower Cambrian period, about 530 million years ago, and since then, has been kept unchanged until today. Nacre is restricted to the conchiferan mollusks, where it occurs in t least three main classes, bivalves, gastropods and cephalopods. The aim of the present study is to investigate whether all nacres are built from the same “macromolecular tools”, proteins of the nacre matrix. To this end, we studied three new nacre models, the freshwater bivalve Unio pictorum, the cephalopod Nautilus macromphalus, and the gastropod Haliotis asinina, to which we applied…
Evolution des biominéralisations nacrées chez les mollusques : caractérisation moléculaire des matrices coquillières du céphalopode nautiloïde Nautil…
2008
In metazoan, molluscan shells are one of the most fascinating examples for the investigation of the calcium carbonate biomineralization phenomenon. These exoskeletons are secreted by the outer epithelium of the calcifying mantle. They are composed of 95% of mineral – calcite and/or aragonite -, the rest of the shells being constituted by a mixture of proteins, glycoproteins and polysaccharides, called the organic matrix. This calcifying matrix is directly involved in biomineralization. This PhD work is focussed on the characterization of organic components associated to the nacreous layer. In molluscs, the nacre is observed in shells of extent species of bivalves, gastropods, cephalopods an…
Evolution of nacre: biochemistry and proteomics of the shell organic matrix of the cephalopod Nautilus macromphalus.
2009
12 pages; International audience; In mollusks, one of the most widely studied shell textures is nacre, the lustrous aragonitic layer that constitutes the internal components of the shells of several bivalves, a few gastropods, and one cephalopod: the nautilus. Nacre contains a minor organic fraction, which displays a wide range of functions in relation to the biomineralization process. Here, we have biochemically characterized the nacre matrix of the cephalopod Nautilus macromphalus. The acid-soluble matrix contains a mixture of polydisperse and discrete proteins and glycoproteins, which interact with the formation of calcite crystals. In addition, a few bind calcium ions. Furthermore, we h…