Hybridization increases mitochondrial production of reactive oxygen species in sunfish
Hybridization increases mitochondrial production of reactive oxygen species in sunfish
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DOI：
10.1111/evo.13254
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发表时间：
2017-06-01
期刊：
影响因子：
3.3
通讯作者：
Scott, Graham R.
中科院分区：
文献类型：
--
作者：
Du, Sherry N. N.;Khajali, Fariborz;Scott, Graham R.
线粒体功能障碍和氧化应激已被认为是潜在的混合故障的可能机制，作为电子传递系统的呼吸复合物中的线粒体-核不相容性的结果。然而，目前还不清楚杂交是否增加线粒体产生活性氧（ROS）。我们使用高分辨率呼吸测定法和荧光测定法对分离的肝线粒体进行检测，以研究南瓜籽（Lepomis gibbosus）和蓝鳃金龟（L. macrochirus）。当呼吸作用由复合物I（而非复合物II）底物支持时，杂交种的ROS释放量高于两个亲本种，并且与脂质过氧化的增加有关，然而，杂交种的氧化磷酸化呼吸能力、磷酸化效率和O（2）动力学介于亲本种之间。通量控制比的能力，电子传递（在未偶联的线粒体中测量）相对于氧化磷酸化的磷酸化系统的限制性影响，减少在杂交。这可能有助于抵消电子传递能力和复合物III活性的损伤，但有助于增加ROS的产生。因此，杂交可以增加线粒体ROS的产生，支持以前的建议，线粒体功能障碍可以诱导氧化应激，从而有助于hybridbreakdown。
Mitochondrial dysfunction and oxidative stress have been suggested to be possible mechanisms underlying hybrid breakdown, as a result of mito-nuclear incompatibilities in respiratory complexes of the electron transport system. However, it remains unclear whether hybridization increases the production of reactive oxygen species (ROS) by mitochondria. We used high-resolution respirometry and fluorometry on isolatedliver mitochondria to examine mitochondrial physiology and ROSemission in naturally occurring hybrids of pumpkinseed (Lepomis gibbosus) and bluegill (L. macrochirus). ROS emission was greater in hybridsthan in both parent species when respiration was supported bycomplex I (but not complex II)substrates, and was associated with increases in lipid peroxidation.However, respiratory capacitiesfor oxidative phosphorylation, phosphorylation efficiency, and O(2)kinetics inhybrids were intermediate between those in parental species. Flux control ratios of capacities for electron transport (measured in uncoupled mitochondria) relative to oxidative phosphorylation suggested that the limiting influence of the phosphorylation system is reduced in hybrids. This likely helped offset impairments in electron transport capacity and complex III activity, but contributed to augmenting ROS production.Therefore, hybridization can increase mitochondrial ROS production, in support of previous suggestions that mitochondrial dysfunction can induce oxidative stress and thus contribute to hybridbreakdown.