Amorphous calcium phosphate in the pupal cuticle of Bactrocera dorsalis Hendel (Diptera: Tephritidae): A new discovery for reconsidering the mineralization of the insect cuticle.
Amorphous calcium phosphate in the pupal cuticle of Bactrocera dorsalis Hendel (Diptera: Tephritidae): A new discovery for reconsidering the mineralization of the insect cuticle.
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DOI：
10.1016/j.jinsphys.2019.103964
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发表时间：
2019-11
影响因子：
2.2
通讯作者：
Jingjing Rong;Yubo Lin;Zhuoxiao Sui;Sijia Wang;Xunfan Wei;J. Xiao;Dawei Huang
中科院分区：
文献类型：
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作者：
Jingjing Rong;Yubo Lin;Zhuoxiao Sui;Sijia Wang;Xunfan Wei;J. Xiao;Dawei Huang
现在人们普遍认为六足动物是从甲壳纲进化而来的。与甲壳类动物普遍存在的钙化外骨骼相比，昆虫的矿化角质层非常罕见。在昆虫表皮的硬化过程中，由邻苯二酚胺驱动的蛋白质交联起主导作用。本文研究了果园常见害虫桔小实蝇（Bactrocera dorsalis）蛹表皮的矿化作用。本文主要描述了B. dorsalis和它的白色叶鞘B.采用高分辨场发射扫描电子显微镜（SEM）和透射电子显微镜（TEM），结合红外光谱（IR）、X射线衍射（XRD）、X射线光电子能谱（XPS）和同步辐射X射线吸收近边结构（XANES）等结构分析技术，对家蝇（Musca domestic）背部和未矿化角质层的结构进行了研究。比较了不同蛹型蛹的热力学和力学性质。结果表明，该虫蛹的蛹型与蛹的蛹型相似。背部含有稳定的无定形磷酸钙（ACP）相，具有高水平的镁，其主要分布在外角质层中，并有助于形成分级的硬化角质层结构。出乎意料的是，这种ACP具有非常低的Ca/P比，并且具有类似于CaHPO 4·2 H2O的组成。蛹角质层的矿化程度。dorsaliswh（约22wt%）显著大于野生型B。dorsalis（约12重量%），这表明生物矿化和酪氨酸介导的晒黑途径之间可能存在联系。这些发现为昆虫角质层的矿化提供了新的证据，这可能为昆虫和甲壳动物角质层硬化分化的进化机制提供新的线索。
It is now widely accepted that Hexapoda emerged from Crustacea. Compared to the ubiquitous calcified exoskeleton in crustaceans, a mineralized cuticle in insects is extremely rare. Catecholamine-driven protein cross-links play a leading role in the sclerotization of insect cuticle. In this study, mineralization was discovered in the pupal cuticle ofBactrocera dorsalis(Diptera: Tephritidae), a common pest of fruit farms. We mainly profiled the features of mineralized pupal cuticles fromB. dorsalisand its white mutantB. dorsaliswhand unmineralized cuticle fromMusca domesticausing high-resolution field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) combined with structural analysis involving infrared (IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and synchrotron X-ray absorption near-edge structure (XANES) spectroscopy. We also compared the thermodynamic and mechanical properties of different pupal cuticles. The results showed that the pupal cuticles ofB. dorsaliscontain a phase of stable amorphous calcium phosphate (ACP) with a high level of magnesium, which is mainly distributed in the exocuticle and assists in the formation of a graded, stiffened cuticle structure. Unexpectedly, this ACP possesses a very low Ca/P ratio and has a composition similar to that of CaHPO4·2H2O. The degree of mineralization in the pupal cuticle ofB. dorsaliswh(approximately 22 wt%) is significantly greater than that of wild-typeB. dorsalis(approximately 12 wt%), which indicates that there may be a connection between the biomineralization and tyrosine-mediated tanning pathways. These findings provide new evidence for the mineralization of the insect cuticle, which may shed new light on the evolutionary mechanism underlying the divergence of cuticle sclerotization between insects and crustaceans.