Characterization of organic matrix components of pearl oyster, Pinctada fucata and their implications in shell formation

• DOI: 10.1007/s11706-008-0026-4
• Publication Date: 2008-06-05T11:09:46Z
• Authors: Chihiro Nogawa; Mami Obara; Megumi Ozawa; Aya Sato; Akiko Watanabe; Ryo Yamazaki; Daishi Yamada; Kana Akiniwa; Tetsuro Samata
• Keywords: Pinctada fucata; Matrix (chemical analysis)

Mollusks make their shells by biomineralization using Ca2+ and CO3 2− from natural environment. In molluscan shells, two types of CaCO3 crystal which are aragonite and calcite form the species-dependent microstructures. It is believed that shell organic matrices act for control of the crystal types and microstructures. Shell of Pinctada fucata is divided into aragonitic nacreous layer and calcitic prismtic layer. In the recent years, several novel matrix components have been identified in pearl oyster shells by subsequent solubilization of the insoluble matrix, even in the nacreous layer which abounds in the data. In them, we focused our attention on a component, of which the N-terminal amino acid sequence was determined, and attempted cloning genes encoding it. As a result, several clones with typical sequence for the ORF (open reading frame) region were identified and the amino acid sequences were deduced. Further analysis of northern hybridization clarified the tissue specific expressions of the transcripts of the identified genes.