Molluscs rapidly repair the damaged shells to prevent further injury, which is vital for their survival after physical or biological aggression. However, it remains unclear how this process is precisely controlled. In this study, we applied scanning electronic microscope and histochemical analysis to examine the detailed shell regeneration process in the pearl oyster Pinctada fucata. It was found that the shell damage caused the mantle tissue to retract, which resulted in relocation of the partitioned mantle zones with respect to their correspondingly secreting shell layers. As a result, the relocated mantle tissue dramatically altered the shell morphology by initiating de novo precipitation of prismatic layers on the former nacreous layers, leading to the formation of sandwich-like “prism-nacre-prism-nacre” structure. Real-time PCR revealed the up-regulation of the shell matrix protein genes, which was confirmed by the thermal gravimetric analysis of the newly formed shell. The increased matrix secretion might have led to the change of CaCO₃ precipitation dynamics which altered the mineral morphology and promoted shell formation. Taken together, our study revealed the close relationship between the physiological activities of the mantle tissue and the morphological change of the regenerated shells.

软体动物会迅速修复受损的外壳以防止进一步受伤，这对于它们在遭受物理或生物攻击后的生存至关重要。然而，目前还不清楚这个过程是如何被精确控制的。在这项研究中，我们应用扫描电子显微镜和组织化学分析来检查珍珠贝Pinctada fucata的详细壳再生过程. 结果发现，壳层损伤导致地幔组织收缩，导致分隔的地幔带相对于它们相应的分泌壳层重新定位。结果，重新定位的地幔组织通过在以前的珠光层上开始棱柱层的从头沉淀，显着改变了壳的形态，导致形成三明治状的“棱柱-珍珠层-棱柱-珍珠层”结构。实时 PCR 揭示了壳基质蛋白基因的上调，新形成的壳的热重分析证实了这一点。基质分泌增加可能导致 CaCO _3的变化降水动力学改变了矿物形态并促进了壳的形成。综上所述，我们的研究揭示了地幔组织的生理活动与再生壳的形态变化之间的密切关系。