Genotype-dependent variation of mitochondrial transcriptional profiles in interpopulation hybrids
Genotype-dependent variation of mitochondrial transcriptional profiles in interpopulation hybrids
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DOI：
10.1073/pnas.0804253105
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发表时间：
2008-10-14
影响因子：
11.1
通讯作者：
Burton, Ronald S.
中科院分区：
文献类型：
--
作者：
Ellison, Christopher K.;Burton, Ronald S.
种群之间的杂交可以破坏基因表达，经常导致有害的杂交表型。海洋桡足类虎脚类种群间杂交适合度的降低被追溯到核基因组和线粒体基因组之间的相互作用。在这里，我们使用RT-qPCR法测定了一系列亲本和近交系线粒体氧化磷酸化途径中涉及的四到六个基因的转录水平。核基因和线粒体编码基因都包括在分析中。虽然所有被研究的基因都在盐胁迫下上调，但只有位于mtDNA上的基因在不同品系之间的表达存在差异。因为线粒体基因是由核基因组中编码的专用RNA聚合酶转录的，所以我们比较了具有不同线粒体RNA聚合酶和mtDNA基因型组合的杂交系的转录水平。携带某些线粒体DNA-线粒体RNA聚合酶基因组合的品系表现出上调线粒体基因以应对低渗胁迫的能力减弱。对转录图谱的影响取决于特定的种群间杂交，并与生存效应相关。我们推测，在F-2杂交种中，线粒体转录系统的破坏可能在杂交种的崩溃中起着核心作用。
Hybridization between populations can disrupt gene expression, frequently resulting in deleterious hybrid phenotypes. Reduced fitness in interpopulation hybrids of the marine copepod Tigriopus californicus has been traced to interactions between the nuclear and mitochondrial genomes. Here, we determine transcript levels of four to six genes involved in the mitochondrial oxidative phosphorylation pathway for a series of parental and inbred hybrid lines using RT-qPCR. Both nuclear and mitochondrial-encoded genes are included in the analysis. Although all genes studied are up-regulated under salinity stress, only expression of genes located on the mtDNA differed among lines. Because mitochondrial genes are transcribed by a dedicated RNA polymerase encoded in the nuclear genome, we compare transcript levels among hybrid lines with different combinations of mitochondrial RNA polymerase and mtDNA genotypes. Lines bearing certain mtDNA-mitochondrial RNA polymerase genotypic combinations show a diminished capacity to up-regulate mitochondrial genes in response to hypoosmotic stress. Effects on the transcriptional profile depend on the specific interpopulation cross and are correlated with viability effects. We hypothesize that disruption of the mitochondrial transcriptional system in F-2 hybrids may play a central role in hybrid breakdown.