Mitochondrial DNA Variation and Selfish Propagation Following Experimental Bottlenecking in Two Distantly Related Caenorhabditis briggsae Isolates
Mitochondrial DNA Variation and Selfish Propagation Following Experimental Bottlenecking in Two Distantly Related Caenorhabditis briggsae Isolates
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DOI：
10.3390/genes11010077
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发表时间：
2020-01
期刊：
影响因子：
3.5
通讯作者：
Josiah T. Wagner;D. Howe;Suzanne Estes;D. Denver
中科院分区：
文献类型：
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作者：
Josiah T. Wagner;D. Howe;Suzanne Estes;D. Denver
理解线粒体DNA（mtDNA）的进化和遗传对动物物种形成和人类疾病模型具有广泛的意义。然而，很少有自然模型存在，可以同时代表mtDNA的传输偏差，突变和拷贝数的变化。某些分离株的线虫小杆线虫Briggsae港口大，自然发生的mtDNA缺失的数百个碱基对影响的NADH脱氢酶亚基5（nduo-5）基因，可能是功能上有害的。这些缺失变异体在遗传漂变条件下可以表现为自私的DNA元件，但是否所有这些大的缺失变异体都以相同的优先方式传播仍不清楚。此外，积累nduo-5缺失倾向不同的分离株之间跨代线粒体DNA进化谱的共享程度也尚不清楚。我们通过实验检测两株C.对不同nduo-5缺失频率的青蟹进行了50代的遗传分析，并进行了总DNA测序以鉴定mtDNA变异。我们观察到C. briggsae分离株，一个潜在的物种特异性模式的拷贝数失调，和一些证据的遗传搭便车在删除轴承分离。我们的结果进一步支持了C. briggsae作为一个实用的模型，用于表征自然发生的mtgenome变异，并有助于理解mtgenome变异如何在动物种群中持续存在，以及它如何在线粒体疾病状态下呈现。
Understanding mitochondrial DNA (mtDNA) evolution and inheritance has broad implications for animal speciation and human disease models. However, few natural models exist that can simultaneously represent mtDNA transmission bias, mutation, and copy number variation. Certain isolates of the nematode Caenorhabditis briggsae harbor large, naturally-occurring mtDNA deletions of several hundred basepairs affecting the NADH dehydrogenase subunit 5 (nduo-5) gene that can be functionally detrimental. These deletion variants can behave as selfish DNA elements under genetic drift conditions, but whether all of these large deletion variants are transmitted in the same preferential manner remains unclear. In addition, the degree to which transgenerational mtDNA evolution profiles are shared between isolates that differ in their propensity to accumulate the nduo-5 deletion is also unclear. We address these knowledge gaps by experimentally bottlenecking two isolates of C. briggsae with different nduo-5 deletion frequencies for up to 50 generations and performing total DNA sequencing to identify mtDNA variation. We observed multiple mutation profile differences and similarities between C. briggsae isolates, a potentially species-specific pattern of copy number dysregulation, and some evidence for genetic hitchhiking in the deletion-bearing isolate. Our results further support C. briggsae as a practical model for characterizing naturally-occurring mtgenome variation and contribute to the understanding of how mtgenome variation persists in animal populations and how it presents in mitochondrial disease states.