Wang Ning, Kinoshita Shigeharu, Riho Chihiro, Maeyama Kaoru, Nagai Kiyohito, Watabe Shugo
Department of Aquatic Bioscience, The University of Tokyo, Tokyo 113-8657, Japan.
Comp Biochem Physiol B Biochem Mol Biol. 2009 Nov;154(3):346-50. doi: 10.1016/j.cbpb.2009.07.012. Epub 2009 Aug 14.
A cultured pearl is produced in a pearl sac which forms layers of cells differentiated from an allograft mantle. Previous investigations claimed that genomic DNAs from grafting tissues were persistent during pearl aquaculture. However, the specific living status of the genes regulating pearl formation has remained unknown. This study examined the expression profiles of six genes encoding nacreous shell matrix proteins (NSMPs) in the pearl sac of aquaculture pearl oyster Pinctada fucata by real-time PCR. The comparative analysis of NSMP gene expression in the pearl sac and reference mantle tissues revealed that only a few NSMP genes maintained high transcription levels in the pearl sac. The impaired transcription levels of the nacrein gene refreshed the previous hypothesis, suggesting that CaCO(3) required for pearl secretion was not from pearl sac cells. Among the examined genes, only the N19 gene attained high expression levels in the pearl sac. These results provide new insights into the molecular mechanisms involved in pearl biogenesis.
养殖珍珠是在珍珠囊中形成的，珍珠囊由同种异体外套膜分化而来的细胞层构成。先前的研究表明，嫁接组织的基因组DNA在珍珠养殖过程中持续存在。然而，调节珍珠形成的基因的具体生存状态仍不清楚。本研究通过实时PCR检测了养殖珍珠牡蛎合浦珠母贝珍珠囊中六个编码珍珠质壳基质蛋白（NSMPs）的基因的表达谱。对珍珠囊和对照外套膜组织中NSMP基因表达的比较分析表明，只有少数NSMP基因在珍珠囊中保持高转录水平。珍珠质基因转录水平的受损刷新了先前的假设，表明珍珠分泌所需的CaCO₃并非来自珍珠囊细胞。在所检测的基因中，只有N19基因在珍珠囊中达到高表达水平。这些结果为珍珠生物合成的分子机制提供了新的见解。
