Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching.
Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching.
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DOI：
10.1371/journal.pone.0152693
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Pringle JR
中科院分区：
文献类型：
--
作者：
Bieri T;Onishi M;Xiang T;Grossman AR;Pringle JR
当暴露于诸如高海水温度的压力时，珊瑚和其他刺胞动物可以由于共生藻类从宿主组织的损失和/或来自藻类的色素的损失而漂白。虽然触发漂白的环境条件是相当众所周知的，但其细胞和分子机制并不清楚。先前的研究已经报道了共生藻类从宿主组织中损失的至少四种不同的细胞机制的发生：藻类的原位降解、藻类从宿主中的胞外释放、含有藻类的宿主细胞的脱离和含有藻类的宿主细胞的死亡。这几种机制对漂白的相对贡献仍然不清楚，也不知道这些相对贡献是否在受到不同类型和/或持续时间的应激的动物中发生变化。在这项研究中，我们使用了克隆种群的小海葵Aiptasia，暴露个人的各种精确控制的压力条件下，并定量评估了几种可能的漂白机制并行。在所有测试的胁迫条件下，除了4°C的急性冷休克外，完整藻类从宿主细胞中排出似乎是迄今为止漂白的主要机制。在急性冷休克，在原位降解的藻类和宿主细胞脱离也变得定量显着，在这些条件下释放的藻类似乎受到严重损害。
When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged.