Fonseca Miguel M, Posada David, Harris D James
Mol Biol Evol. 2008 May;25(5):805-8. doi: 10.1093/molbev/msn050. Epub 2008 Feb 21.
After analyzing the base composition asymmetry of coding regions in vertebrate mitochondria, we identified 2 fishes, Albula glossodonta and Bathygadus antrodes, with inverted compositional patterns. Both species appear to have an unusual control region (CR), and in B. antrodes, it has switched from the light strand to the heavy strand. To our knowledge, this is the first report in vertebrates of inverted mitochondrial replication, caused by an inversion of the CR. These findings support the strand-asymmetric model of mtDNA replication and suggest that vertebrate mtDNA can tolerate globally reversed mutational pressures. In addition, we propose that nucleotide bias is not strand specific but that it depends on the location of the CR.
在分析了脊椎动物线粒体编码区的碱基组成不对称性后，我们鉴定出两种鱼类，即光齿北梭鱼和深海黑头鱼，它们具有反向的组成模式。这两个物种似乎都有一个不寻常的控制区（CR），在深海黑头鱼中，它已从轻链转换为重链。据我们所知，这是脊椎动物中首次报道由CR倒位引起的线粒体复制倒位。这些发现支持了线粒体DNA（mtDNA）复制的链不对称模型，并表明脊椎动物mtDNA可以耐受整体反转的突变压力。此外，我们提出核苷酸偏好不是链特异性的，而是取决于CR的位置。
