Search results for "évolution"

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…