Mineral-bearing vesicle transport in sea urchin embryos
Mineral-bearing vesicle transport in sea urchin embryos
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DOI：
10.1016/j.jsb.2015.09.017
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发表时间：
2015-12-01
影响因子：
3
通讯作者：
Addadi, Lia
中科院分区：
文献类型：
--
作者：
Vidavsky, Netta;Masic, Admir;Addadi, Lia
海胆胚胎从海水中吸收钙。这种钙以浓缩形式沉积在上皮细胞和间充质细胞中的颗粒承载囊泡中。在这里，我们使用在体内钙黄绿素标记和共聚焦拉曼光谱，以及冷冻FIB-SEM三维结构重建，调查的过程中发生的内部空腔的胚胎，囊胚腔。我们证明，钙黄绿素染色的颗粒也存在于囊胚腔内的丝状伪足网络。同步荧光成像和拉曼光谱显示，这些颗粒确实含有钙矿物质。通过跟踪这些颗粒的运动，我们发现，上皮细胞和初级间充质细胞中的颗粒几乎不移动，但在丝状伪足网络中的颗粒移动很长的距离。然而，我们不能检测到任何单向运动的丝状伪足颗粒。我们还表明存在的矿物质含有多泡囊泡，也在丝状伪足网络。我们的结论是，丝状伪足网络是一个不可分割的一部分，矿物运输过程中，也可能螯合钙和其他离子。尽管大部分螯合的钙沉积在矿化骨骼中，但大量钙用于其他目的，并且可能暂时储存在这些膜划定的细胞内沉积物中。(C)2015 Elsevier Inc. All rights reserved.
Sea urchin embryos sequester calcium from the sea water. This calcium is deposited in a concentrated form in granule bearing vesicles both in the epithelium and in mesenchymal cells. Here we use in vivo calcein labeling and confocal Raman spectroscopy, as well as cryo-FIB-SEM 3D structural reconstructions, to investigate the processes occurring in the internal cavity of the embryo, the blastocoel. We demonstrate that calcein stained granules are also present in the filopodial network within the blastocoel. Simultaneous fluorescence imaging and Raman spectroscopy show that these granules do contain a calcium mineral. By tracking the movements of these granules, we show that the granules in the epithelium and primary mesenchymal cells barely move, but those in the filopodial network move long distances. We could however not detect any unidirectional movement of the filopodial granules. We also show the presence of mineral containing multivesicular vesicles that also move in the filopodial network. We conclude that the filopodial network is an integral part of the mineral transport process, and possibly also for sequestering calcium and other ions. Although much of the sequestered calcium is deposited in the mineralized skeleton, a significant amount is used for other purposes, and this may be temporarily stored in these membrane-delineated intracellular deposits. (C) 2015 Elsevier Inc. All rights reserved.