Mitochondrial-Nuclear Epistasis Impacts Fitness and Mitochondrial Physiology of Interpopulation Caenorhabditis briggsae Hybrids.
Mitochondrial-Nuclear Epistasis Impacts Fitness and Mitochondrial Physiology of Interpopulation Caenorhabditis briggsae Hybrids.
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DOI：
10.1534/g3.115.022970
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发表时间：
2015-11-19
期刊：
影响因子：
--
通讯作者：
Ross J
中科院分区：
文献类型：
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作者：
Chang CC;Rodriguez J;Ross J
为了确定最早的遗传变化，沉淀物种的形成，这是有用的，以研究遗传不相容性，当不相容的等位基因组合在一个种群间杂交只会导致轻微的功能障碍。这种在线虫物种Caelophabditis briggsae内的杂交已经被认为导致针对核和线粒体等位基因的某些组合的选择，提高了线粒体-核（线粒体）上位性降低杂交适合度的可能性。为了验证这一假设，创建了细胞质-核杂种（cybrids），以有目的地破坏任何上位相互作用。对胞质杂种的实验分析表明，线粒体不和谐可导致生殖力下降、脂质含量增加和线粒体活性氧水平增加。许多这些影响是不对称的横向，如预期的，如果细胞质核Dobzhansky-Muller不相容性存在。一个这样的效果是一致的解释，破坏共同进化的线粒体和核基因座影响线粒体功能和生物体的健身。这些发现加强了对促成物种形成过程的遗传不相容性的起源、身份和维持的研究。
In order to identify the earliest genetic changes that precipitate species formation, it is useful to study genetic incompatibilities that cause only mild dysfunction when incompatible alleles are combined in an interpopulation hybrid. Such hybridization within the nematode species Caenorhabditis briggsae has been suggested to result in selection against certain combinations of nuclear and mitochondrial alleles, raising the possibility that mitochondrial–nuclear (mitonuclear) epistasis reduces hybrid fitness. To test this hypothesis, cytoplasmic–nuclear hybrids (cybrids) were created to purposefully disrupt any epistatic interactions. Experimental analysis of the cybrids suggests that mitonuclear discord can result in decreased fecundity, increased lipid content, and increased mitochondrial reactive oxygen species levels. Many of these effects were asymmetric with respect to cross direction, as expected if cytoplasmic–nuclear Dobzhansky-Muller incompatibilities exist. One such effect is consistent with the interpretation that disrupting coevolved mitochondrial and nuclear loci impacts mitochondrial function and organismal fitness. These findings enhance efforts to study the genesis, identity, and maintenance of genetic incompatibilities that precipitate the speciation process.