Intracellular calcium compartmentation in the mineral forming organisms Porcellio scaber (Crustacea), Magellania venosa (Brachiopoda) and Emiliania huxleyi (Haptophyta).

矿物质形成生物 Porcellio scaber（甲壳纲）、Magellania venosa（腕足纲）和 Emiliania huxleyi（弓形植物）中的细胞内钙区室。

• 批准号: 389085271
• 负责人: Privatdozent Dr. Andreas Ziegler, Ph.D.
• 金额: --
• 依托单位: Zentrale Einrichtung Elektronenmikroskopie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/389085271?language=en
• 关键词: Intracellular; calcium; compartmentation; mineral; forming

Formation of biogenic carbonates is one of the most important processes in the biosphere. It has led to the formation of vast limestone deposits representing an important sink for atmospheric CO2. The cellular mechanisms of shell formation involve the transport of calcium through cells to the site of mineralisation. This transport may occur either in the form of ions or as an amorphous mineral precursor phase formed within the cells. In both cases, transport has to take place within cell organelles to avoid high toxic calcium-ion concentrations in the cytosol. However, our knowledge on intracellular calcium compartmentation during biomineralisation is fragmentary. In particular, vesicular structures and the endoplasmatic reticulum have been suggested to contribute to the calcium transport. In addition, the type of organelles involved can vary, depending on the organism and mineralized tissue. Therefore, we plan to investigate the subcellular distribution of calcium within biomineralising cells, with the aim to identify the organelles contributing to calcium transport. To account for possible differences between organisms and tissues, it is planned to investigate five different cell systems. Three of them from the terrestrial crustacean Porcellio scaber: 1) the anterior sternal epithelium, in which calcium transport rates are notably high during formation and resorption of large calcium carbonate reservoirs, 2) the hypodermis of the partes incisivae of the mandibles, as an example of calcium phosphate formation, and 3) the epithelium of the hepatopancreas that, after the animal has ingested its exuviae, transports mineral from the CaCO3-containing exuviae to the hemolymph. Here, it is of particular interest that one cell type accumulates heavy metals within lysosomal granules, raising the possibility that these are also involved in calcium transport. Furthermore, 4) it is planned to investigate the mantle epithelium of the brachiopod Magellania venosa, and 5) the marine coccolithophorid alga Emiliania huxleyi. Brachiopods exist from the early Cambrium with world wide geographic distribution. There fossil shells represent an immense archive for isotope signatures, that are important for reconstruction of paleo-climatic factors and that, however, can be influenced by cellular mechanisms. Emiliania huxleyi is responsible for one third of the marine CaCO3 production, and is an example of calcite formation within an intracellular organelle.For sample preparation high pressure freezing and cryo-ultramicrotomy will be used. Structural aspects and the distribution of calcium will be analysed by cryo-scanning electron microscopy, electron probe microanalysis and energy filtered transmission electron microscopy. The aim of the proposed investigations is to attain new insights in the mechanisms of cellular calcium transport in biomineralisation and its functional diversity and conservation during evolution.

生物碳酸盐的形成是生物圈中最重要的过程之一。它导致了大量石灰石沉积物的形成，是大气CO2的重要汇。壳形成的细胞机制涉及钙通过细胞运输到矿化位点。这种运输可以以离子的形式或作为细胞内形成的无定形矿物前体相发生。在这两种情况下，运输必须发生在细胞器内，以避免高毒性的钙离子浓度的细胞质。然而，我们对生物矿化过程中细胞内钙区室化的认识是零碎的。特别是，泡状结构和内质网已被认为有助于钙的运输。此外，所涉及的细胞器的类型可以根据生物体和矿化组织而变化。因此，我们计划研究钙在生物矿化细胞内的亚细胞分布，目的是确定有助于钙转运的细胞器。为了解释生物体和组织之间可能存在的差异，计划研究五种不同的细胞系统。其中三个来自陆生甲壳动物Porcellio scaber：1）前胸骨上皮，其中在大的碳酸钙储库的形成和再吸收期间钙转运速率显著高，2）下颌骨切缘部分的皮下组织，作为磷酸钙形成的实例，和3）肝胰腺的上皮，在动物已经摄入其分泌物之后，将矿物质从含CaCO3的分泌物运输到血淋巴。在这里，特别令人感兴趣的是，一种细胞类型在溶酶体颗粒内积累重金属，提高了这些细胞也参与钙转运的可能性。此外，4）计划调查腕足动物Magellania venosa的外套膜上皮，和5）海洋球石藻类Emiliania huxleyi。腕足类自早白垩世就存在，地理分布广泛。这些化石贝壳代表了一个巨大的同位素签名档案，这对重建古气候因素很重要，但是，可能会受到细胞机制的影响。Emiliania huxleyi负责海洋碳酸钙生产的三分之一，并且是细胞内细胞器内方解石形成的一个例子。将通过冷冻扫描电子显微镜、电子探针显微分析和能量过滤透射电子显微镜分析钙的结构方面和分布。提出的调查的目的是获得新的见解在生物矿化和其功能的多样性和保护过程中的细胞钙运输的机制。

项目成果

Terebratulide brachiopod shell biomineralization by mantle epithelial cells.

• DOI: 10.1016/j.jsb.2019.05.002
• 发表时间: 2019-08
• 期刊: Journal of structural biology
• 影响因子: 3
• 作者: M. S. Roda;Andreas Ziegler;E. Griesshaber;Xiaofei Yin;U. Rupp;Martina Greiner;D. Henkel;V. Häussermann;Anton Eisenhauer;J. Laudien;W. Schmahl

Intracellular calcium phosphate deposits contribute to transcellular calcium transport within the hepatopancreas of Porcellio scaber.

细胞内磷酸钙沉积物有助于 Porcellio scaber 肝胰腺内的跨细胞钙转运

• DOI: 10.1016/j.jsb.2020.107613
• 发表时间: 2020
• 期刊: Journal of structural biology
• 影响因子: 3
• 作者: P. Walther;A. Ziegler
• 通讯作者: A. Ziegler

The epidermis cells of mandible teeth in the terrestrial isopod Porcellio scaber: Differentiations for mineralisation with calcium phosphate and carbonate.

陆生等足动物 Porcellio scaber 下颌牙齿的表皮细胞：磷酸钙和碳酸盐矿化的分化

• DOI: 10.1016/j.asd.2021.101101
• 发表时间: 2021
• 期刊: Arthropod structure & development
• 影响因子: 2
• 作者: Nutz B;Rupp U;Walther P;Ziegler A
• 通讯作者: Ziegler A