Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai, People's Republic of China.
Class 1, 2016 Marine Biology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, People's Republic of China.
Biotechnol Appl Biochem. 2019 Jul;66(4):545-554. doi: 10.1002/bab.1752. Epub 2019 Jul 8.
Biological mineralization is a highly programmed process in which inorganic minerals reassociate under the strict control of the extracellular matrix to form minerals with special functions and patterns. Shells are biominerals, and their synthesis is finely regulated by organic matrix including matrix proteins, polysaccharides, lipids, pigments, free amino acids, and small peptides. In this study, two matrix protein genes, hic14 and hic19, were isolated from the mantle of the mussel Hyriopsis cumingii. Tissue expression analysis showed that both proteins were expressed mainly in the mantle, and in situ hybridization of mantle tissues showed that they were specifically expressed in the dorsal epithelial cells of mantle pallial. Therefore, hic14 and hic19 were both nacreous layer matrix proteins. In the pearl insertion experiment, hic14 and hic19 kept low expression during pearl sac formation and disordered calcium carbonate deposition, and increased significantly during pearl nacre accumulation, which showed that both proteins participated in the mineralization of pearl nacre. In the RNA interference experiment, shell nacre tablet growth was inhibited after crystal nucleation due to the decreased expression of hic14, and crystal morphology and arrangement of nacre were highly modified after expression of hic19 was inhibited. These results provided further evidence that both hic14 and hic19 participated in nacreous layer biomineralization.
生物矿化是一个高度程序化的过程，其中无机矿物质在细胞外基质的严格控制下重新组合，形成具有特殊功能和模式的矿物质。贝壳是生物矿化产物，其合成受到有机基质的精细调控，包括基质蛋白、多糖、脂质、色素、游离氨基酸和小肽。在本研究中，从贻贝外套膜中分离出了两个基质蛋白基因 hic14 和 hic19。组织表达分析表明，这两种蛋白主要在外套膜中表达，原位杂交显示它们在外套膜的背侧上皮细胞中特异性表达。因此，hic14 和 hic19 都是珍珠层基质蛋白。在珍珠插入实验中，hic14 和 hic19 在珍珠囊形成和无序碳酸钙沉积期间保持低表达，在珍珠母质积累期间显著增加，表明这两种蛋白均参与了珍珠母质的矿化。在 RNA 干扰实验中，由于 hic14 表达降低，导致晶体成核后贝壳珍珠层薄片的生长受到抑制，而 hic19 表达抑制后，珍珠层的晶体形态和排列发生了高度改变。这些结果进一步证明 hic14 和 hic19 均参与了珍珠层生物矿化。
