Cytonuclear conflict in interpopulation hybrids: the role of RNA polymerase in mtDNA transcription and replication
Cytonuclear conflict in interpopulation hybrids: the role of RNA polymerase in mtDNA transcription and replication
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DOI：
10.1111/j.1420-9101.2009.01917.x
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发表时间：
2010-03-01
影响因子：
2.1
通讯作者：
Burton, R. S.
中科院分区：
文献类型：
--
作者：
Ellison, C. K.;Burton, R. S.
生物体适应性需要细胞核和线粒体基因组的功能整合。结构和调控元件在谱系内共同进化，一些研究发现种群间杂交破坏有丝核相互作用。由于线粒体RNA聚合酶（mtRPOL）在线粒体DNA （mtDNA）的复制和转录中都起着关键作用，因此mtRPOL与mtDNA中共同进化的调控位点之间的相互作用可能是线粒体核整合的核心。在这里，我们在加利福尼亚虎爪类不同种群之间产生种群间杂交，以获得具有不同mtRPOL和mtDNA组合的品系。用mtDNA拷贝数和ATP6 （mtDNA）基因表达对品系进行评分。我们发现线粒体转录反应和mtDNA拷贝数之间存在基因型依赖的负相关。我们认为，在杂交中观察到的mtDNA拷贝数的增加和mtDNA转录的减少反映了mtRPOL的调节作用；根据有丝核基因型的不同，杂交可能会破坏线粒体基因组转录和复制之间的正常平衡。
Organismal fitness requires functional integration of nuclear and mitochondrial genomes. Structural and regulatory elements coevolve within lineages and several studies have found that interpopulation hybridization disrupts mitonuclear interactions. Because mitochondrial RNA polymerase (mtRPOL) plays key roles in both mitochondrial DNA (mtDNA) replication and transcription, the interaction between mtRPOL and coevolved regulatory sites in the mtDNA may be central to mitonuclear integration. Here, we generate interpopulation hybrids between divergent populations of the copepod Tigriopus californicus to obtain lines having different combinations of mtRPOL and mtDNA. Lines were scored for mtDNA copy number and ATP6 (mtDNA) gene expression. We find that there is a genotype-dependent negative association between mitochondrial transcriptional response and mtDNA copy number. We argue that an observed increase in mtDNA copy number and reduced mtDNA transcription in hybrids reflects the regulatory role of mtRPOL; depending on the mitonuclear genotype, hybridization may disrupt the normal balance between transcription and replication of the mitochondrial genome.