Thermal stress promotes host mitochondrial degradation in symbiotic cnidarians: are the batteries of the reef going to run out?
Thermal stress promotes host mitochondrial degradation in symbiotic cnidarians: are the batteries of the reef going to run out?
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DOI：
10.1371/journal.pone.0039024
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Dove SG
中科院分区：
文献类型：
--
作者：
Dunn SR;Pernice M;Green K;Hoegh-Guldberg O;Dove SG
刺胞动物和它们的鞭毛类共生体共生关系是热带珊瑚礁形成的基础，但环境条件的快速变化可能会破坏这种关系。尽管一些研究得出结论认为，由于光合作用的解耦，共生关系的破裂始于共生体内活性氧（ROS）的产生增加，但其他研究报道了通过各种宿主细胞衍生机制释放有活力的共生体。我们探索了另一种模型，关注宿主刺胞细胞线粒体完整性在热应激下的变化。线粒体通常被比作细胞的电池，以ATP的形式提供能量，并控制细胞途径的激活和ROS的产生。利用共聚焦和电子显微镜比较了宿主线粒体的整体形态与相关共生体在实验热应力下的形态。结果表明，高温胁迫诱导刺胞动物宿主线粒体的降解与共生体细胞的降解无关。通过使用定量RT-PCR测量与电子传递和ATP合成相关基因的表达变化，还评估了宿主线粒体断裂的潜在位点。降解的主要位点似乎是电子传递链复合物III的下游，宿主细胞色素c和ATP合成酶的表达显著降低。表达减少的后果可能会限制宿主减轻ROS生成和维持细胞器完整性和细胞能量供应的能力。宿主线粒体的破坏、细胞稳态和随后的细胞死亡，与共生完整性无关，突出了宿主对热应激反应和共生功能障碍的重要性，这对理解珊瑚礁如何在气候变化中生存具有重大意义。
The symbiotic relationship between cnidarians and their dinoflagellate symbionts, Symbiodinium spp, which underpins the formation of tropical coral reefs, can be destabilized by rapid changes to environmental conditions. Although some studies have concluded that a breakdown in the symbiosis begins with increased reactive oxygen species (ROS) generation within the symbiont due to a decoupling of photosynthesis, others have reported the release of viable symbionts via a variety of host cell derived mechanisms. We explored an alternative model focused upon changes in host cnidarian mitochondrial integrity in response to thermal stress. Mitochondria are often likened to being batteries of the cell, providing energy in the form of ATP, and controlling cellular pathway activation and ROS generation. The overall morphology of host mitochondria was compared to that of associated symbionts under an experimental thermal stress using confocal and electron microscopy. The results demonstrate that hyperthermic stress induces the degradation of cnidarian host mitochondria that is independent of symbiont cellular deterioration. The potential sites of host mitochondrial disruption were also assessed by measuring changes in the expression of genes associated with electron transport and ATP synthesis using quantitative RT-PCR. The primary site of degradation appeared to be downstream of complex III of the electron transport chain with a significant reduction in host cytochrome c and ATP synthase expression. The consequences of reduced expression could limit the capacity of the host to mitigate ROS generation and maintain both organelle integrity and cellular energy supplies. The disruption of host mitochondria, cellular homeostasis, and subsequent cell death irrespective of symbiont integrity highlights the importance of the host response to thermal stress and in symbiosis dysfunction that has substantial implications for understanding how coral reefs will survive in the face of climate change.
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影响因子：
4.3
作者：
Gogvadze, Vladimir;Orrenius, Sten;Zhivotovsky, Boris
通讯作者：
Zhivotovsky, Boris
影响因子：
3.8
作者：
Donepudi, M;Grütter, MG
通讯作者：
Grütter, MG
影响因子：
2
作者：
Giddings, TH
通讯作者：
Giddings, TH
DOI：
10.1196/annals.1341.022
发表时间：
2005-01-01
期刊：
COMMUNICATIVE CARDIAC CELL
影响因子：
--
作者：
Honda, HM;Korge, P;Weiss, JN
通讯作者：
Weiss, JN
影响因子：
2.9
作者：
Buxton, Lucy;Takahashi, Shunichi;Ralph, Peter J.
通讯作者：
Ralph, Peter J.