Pmarg‐Pearlin is a Matrix Protein Involved in Nacre Framework Formation in the Pearl OysterPinctada margaritifera

Abstract

The shell of pearl oysters is organized in multiple layers of CaCO(3) crystallites packed together in an organic matrix. Relationships between the components of the organic matrix and mechanisms of nacre formation currently constitute the main focus of research into biomineralization. In this study, we characterized the pearlin protein from the oyster Pinctada margaritifera (Pmarg); this shares structural features with other members of a matrix protein family, N14/N16/pearlin. Pmarg pearlin exhibits calcium- and chitin-binding properties. Pmarg pearlin transcripts are distinctively localized in the mineralizing tissue responsible for nacre formation. More specifically, we demonstrate that Pmarg pearlin is localized within the interlamellar matrix of nacre aragonite tablets. Our results support recent models for multidomain matrix protein involvement in nacreous layer formation. We provide evidence here for the existence of a conserved family of nacre-associated proteins in Pteriidae, and reassess the evolutionarily conserved set of biomineralization genes related to nacre formation in this taxa.

Evidence of donor effect on cultured pearl quality from a duplicated grafting experiment onPinctada margaritiferausing wild donors

“…Such differences in aragonite thickness and/or shell deposit rate have been observed for P. maragaritifera grown at different trophic levels (Linard et al 2011). This ability is driven by the mineralizing properties of the calcifying tissue (mantle for the shell and pearl sac for the cultured pearl), which has been actively studied for P. margaritifera in recent years (Joubert et al 2010;Marie et al 2011;Montagnani et al 2011). Given these results and the importance of cultured nacre thickness (pearl size) for the value of a cultured pearl, further studies should be conducted, such as qPCR-based expression studies of candidate genes implicated in high biomineralisation capabilities.…”

Novel Molluskan Biomineralization Proteins Retrieved from Proteomics: A Case Study with Upsalin

“…Upsalin has a predicted signal peptide with a cleavage site between the positions 16 and 17 and a putative transmembrane region (positions [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The mature form of the protein consists of 109 aa residues and has a theoretical molecular weight of 12.3 kDa.…”

“…This one-to-one protein approach enriched information on the primary structures of many shell proteins in the last decade. [1] Today, not all shell proteins have the same status: some of them have been fully characterized at both transcriptional and protein levels, and are firmly established as shell proteins (typical examples include prismalin-14 [13] and pearlin [14] ). Some proteins are true shell proteins, but because they have been sequenced directly, information at the transcript level is not available.…”

A History of the Cultured Pearl Industry

“…Parallel studies in the field of life science using genetic research have recently made rapid progress. In pearl research, genome analysis is also making rapid progress (Shen and Morse, 1997;Kono et al, 2000;Zhang and Zhang, 2003;Wang et al, 2008Wang et al, , 2009, and there have been many significant studies in the field of biomineralization, such as the elucidation of the nacre-forming mechanism (Suzuki et al, 2009;Jackson et al, 2010;Joubert et al, 2010;Kinoshita et al, 2011;Fang et al, 2011;Gardner et al, 2011;Montagnani et al, 2011;Isowa et al, 2012;Marie et al, 2012;Wang et al, 2012). An important milepost was reached in 2012 when, in a world first, a group including the Okinawa Institute of Science and Technology Graduate University and others performed draft genome sequencing of the Japanese Akoya oyster (Takeuchi et al, 2012).…”