Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
J Exp Biol. 2018 Sep 20;221(Pt 18):jeb183236. doi: 10.1242/jeb.183236.
Species of the Ostreidae family are key ecosystem engineers and many of them - including and - are commercially important aquaculture species. Despite similarities in their morphology and ecology, these two species differ in their ability to defend against pathogens, potentially reflecting species-specific differential specialization of hemocytes on immune defense versus biomineralization. To test this hypothesis, we investigated the expression levels of immune- and biomineralization-related genes as well as mineralogical and mechanical properties of the shells and the calcium sequestration ability of the hemocytes of and The expression of biomineralization-related genes was higher in than in in multiple tissues including the mantle edge and hemocytes, while the expression of immune genes was higher in the hemocytes of Hemocytes of contained more calcium (stored intracellularly as calcium carbonate mineral) compared with those of Analysis of the adult shells showed that the crystallinity of calcite was higher and the laths of the foliated layer of the shell were thicker in than in Mechanically, the shells of were stiffer, harder and stronger than those of Taken together, our results show that the species-specific differences in physiology (such as disease resistance and exoskeleton properties) are reflected at the cellular and molecular levels in the differential specialization of hemocytes on potentially competing functions (immunity and biomineralization) as well as different expression profiles of other tissues involved in biomineralization (such as the mantle edge).
牡蛎科的物种是关键的生态系统工程师，其中许多物种——包括 和 ——都是具有商业重要性的水产养殖物种。尽管这两个物种在形态和生态上有相似之处，但它们在抵御病原体的能力上有所不同，这可能反映了血细胞在免疫防御和生物矿化方面的特定物种差异的专业化。为了验证这一假设，我们研究了 和 免疫和生物矿化相关基因的表达水平，以及贝壳的矿物学和力学性质和血细胞的钙螯合能力。在包括边缘膜和血细胞在内的多个组织中， 比 中与生物矿化相关的基因表达更高，而 中免疫基因的表达更高。 血细胞中含有更多的钙（以碳酸钙矿物的形式储存在细胞内），而 血细胞中则含有更多的钙。对成年贝壳的分析表明， 中方解石的结晶度更高，贝壳分层层的薄片更厚。从力学角度来看， 贝壳比 贝壳更硬、更硬、更强。综上所述，我们的研究结果表明，物种特异性差异在生理上（如疾病抗性和外骨骼特性）在血细胞的潜在竞争功能（免疫和生物矿化）上的专业化差异以及其他参与生物矿化的组织（如边缘膜）的不同表达谱上反映在细胞和分子水平上。
