title: The inner-shell film: an immediate structure participating in pearl oyster shell formation.
abstract: In mollusks, the inner shell film is located in the shell-mantle zone and it is important in shell formation. In this study, we found that the film was composed of two individual films under certain states and some columnar structures were observed between the two individual films. The inner shell film was separated with the process of ethylenediaminetetraacetic acid (EDTA) treatment and the film proteins were extracted. Amino acid analysis showed that the film proteins may consist of shell framework proteins. The calcite crystallization experiment showed that the film proteins could inhibit the growth of calcite, while the CaCO(3) precipitation experiment showed that the film proteins could accelerate the rate of CaCO(3) precipitation. All these results suggested that the film plays an important role in shell formation. It may facilitate the aragonite formation by inhibiting the growth of calcite and accelerate the shell growth by promoting the precipitation of CaCO(3) crystals.
authors.affiliation: Institute of Marine Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
authors.forename: Zhenguang
authors.initials: Z
authors.lastname: Yan
authors.forename: Zhuojun
authors.initials: Z
authors.lastname: Ma
authors.forename: Guilan
authors.initials: G
authors.lastname: Zheng
authors.forename: Qiaoli
authors.initials: Q
authors.lastname: Feng
authors.forename: Hongzhong
authors.initials: H
authors.lastname: Wang
authors.forename: Liping
authors.initials: L
authors.lastname: Xie
authors.forename: Rongqing
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000596:Amino Acids; D000818:Animals; D002119:Calcium Carbonate / Q000737:chemistry; D011232:Chemical Precipitation; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D049911:Pinctada / Q000033:anatomy & histology* / Q000737:chemistry / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility
chemical_list: D000596:Amino Acids; D011506:Proteins; D002119:Calcium Carbonate