Expression profiles of nine biomineralization genes and their relationship with pearl nacre thickness in the pearl oyster,Pinctada fucata martensiiDunker

Abstract

Pinctada fucata martensii is an ideal animal for study of biomineralization. Although dozens of genes have been identified, the molecular mechanism of biomineralization remains still unclear. The purpose here was to discover the expression profiles of nine biomineralization genes in related tissues: mantle edge (ME), mantle centre (MC) and pearl sac (PS), and to explore the relationships between expression level and nacre thickness. The expression levels of seven genes (ACCBP, aspein, CaM, EFCBP, KRMP, nacrein and prismalin‐14) showed no significant difference between ME and MC, but were significantly higher than those in PS. The expression level of N19 was the same in ME and PS, significantly higher than that in MC. However, msi60 in ME, MC and PS showed no significant differences in expression level. In addition, the correlations of expression levels between ME, MC and PS were highly significant, indicating that there are some similar function and mechanism among the three tissues. Also the nine genes had significant correlation of expression levels between one another. Furthermore, no other genes from oysters which produced pearls of different grades showed significant difference in the expression level, except CaM in MC, which had significantly higher expression level in the medium pearl grade than in the plain nucleus grade. Moreover, the expression level of msi60 in MC of host oyster was significantly correlated with produced pearl layer thickness, suggesting that msi60 might play an important role in pearl formation and host oyster may also participate in the development of pearl.

Donor and recipient contribution to phenotypic traits and the expression of biomineralisation genes in the pearl oyster model Pinctada margaritifera

“…The recipient oyster regulates the metabolism of the pearl sac by supplying nutrients during the period of culture and thus regulates the expression of the biomineralisation genes, especially those implicated in the aragonite layers 22 . High biomineralisation capabilities may have contributed to a greater nacre deposition, as already observed in P. maxima 23 – 25 and P. fucata 26 . The recipient oyster can be compared to the rootstock of a grafted plant, with recipient oyster and rootstock each corresponding to a grafted organism.…”

Whole transcriptome sequencing and biomineralization gene architecture associated with cultured pearl quality traits in the pearl oyster, Pinctada margaritifera

“…A considerable number of studies have focused on the identification of genes involved in aragonite and/or calcite formation in pearl oyster species and other bivalves capable of shell mineralisation [20, 22, 46, 47, 48–54]. Nonetheless, it has proven difficult to extrapolate the role of key actors involved in determining cultured pearl quality across studies.…”

Effects of replacing microalgae with an artificial diet on pearl production traits and mineralization-related gene expression in pearl oyster Pinctada fucata martensii

“…Nacrein is critical in regulating the binding of calcium ions and catalysing the fixation of CO 2 to generate sufficient CaCO 3 anions for CaCO 3 production as the pearl layer constitution (Miyamoto et al, 1996(Miyamoto et al, , 2005Ning et al, 2009). MSI60 forms the prismatic and nacreous layers (Sato et al, 2013) and might be important in pearl formation; moreover, the host oyster may also participate in pearl development (Gu et al, 2014b), and the expression levels of MSI60 mRNA have been shown to positively correlate with pearl weight in P. fucata martensii (Zhan, Yu, Shi, Gu & Wang, 2016). Chitin-binding proteins are able to interact with both chitin and minerals (Liu, 2015).…”