title: Expression of genes responsible for biomineralization of Pinctada fucata during development.
abstract: This study compares the expression levels of nacrein, N16, MSI60, Prismalin-14, aspein and MSI31 genes during the ontogeny of Pinctada fucata. Several novel findings were obtained: 1) The early calcitic prismatic layer was distinguished as a thin membrane-like structure. 2) Initial formation of the nacreous layer started from the mantle pallial region at the age of 31days. 3) 18S rRNA of P. fucata was determined to be more suitable as a real-time PCR reference gene compared with GAPDH and beta-actin genes. 4) A relationship was recognized between the expression levels of the above six organic matrix genes and biomineralization of the larval shell. The lack of calcite in the shells of the veliger and pediveliger stages, when MSI31 and Prismalin-14 genes were expressed, makes a role of polymorph control by these genes less likely. The hypothetical involvement of N16 and MSI60 proteins in aragonitic nacreous layer formation was corroborated by the expression levels of N16 and MSI60 genes during ontogeny. Our results are important with respect to the control of CaCO(3) crystal polymorphism and shell microstructures in P. fucata.
authors.affiliation: Laboratory of Cell Biology, Graduate School of Environmental Health, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Takuma
authors.initials: T
authors.lastname: Nishida
authors.forename: Hideo
authors.initials: H
authors.lastname: Aoki
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Samata
mesh_terms: D000818:Animals; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008903:Minerals / Q000378:metabolism*; D049911:Pinctada / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics / Q000302:isolation & purification
chemical_list: D008903:Minerals; D012313:RNA