Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
BMC Evol Biol. 2010 Oct 7;10:300. doi: 10.1186/1471-2148-10-300.
Complete mitochondrial genome sequences have become important tools for the study of genome architecture, phylogeny, and molecular evolution. Despite the rapid increase in available mitogenomes, the taxonomic sampling often poorly reflects phylogenetic diversity and is often also biased to represent deeper (family-level) evolutionary relationships.
We present the first fully sequenced ant (Hymenoptera: Formicidae) mitochondrial genomes. We sampled four mitogenomes from three species of fire ants, genus Solenopsis, which represent various evolutionary depths. Overall, ant mitogenomes appear to be typical of hymenopteran mitogenomes, displaying a general A+T-bias. The Solenopsis mitogenomes are slightly more compact than other hymentoperan mitogenomes (~15.5 kb), retaining all protein coding genes, ribosomal, and transfer RNAs. We also present evidence of recombination between the mitogenomes of the two conspecific Solenopsis mitogenomes. Finally, we discuss potential ways to improve the estimation of phylogenies using complete mitochondrial genome sequences.
The ant mitogenome presents an important addition to the continued efforts in studying hymenopteran mitogenome architecture, evolution, and phylogenetics. We provide further evidence that the sampling across many taxonomic levels (including conspecifics and congeners) is useful and important to gain detailed insights into mitogenome evolution. We also discuss ways that may help improve the use of mitogenomes in phylogenetic analyses by accounting for non-stationary and non-homogeneous evolution among branches.
完整的线粒体基因组序列已成为研究基因组结构、系统发育和分子进化的重要工具。尽管可利用的线粒体基因组数量迅速增加，但分类学采样往往不能很好地反映系统发育多样性，而且往往也偏向于代表更深层次（科级水平）的进化关系。
我们首次完整测序了蚂蚁（膜翅目：蚁科）的线粒体基因组。我们从三种火蚁属（Solenopsis）的四个物种中采样了四个线粒体基因组，它们代表了各种进化深度。总体而言，蚂蚁线粒体基因组似乎与膜翅目线粒体基因组典型特征一致，表现出普遍的 A+T 偏向性。火蚁的线粒体基因组比其他膜翅目线粒体基因组稍小（约 15.5kb），保留了所有蛋白质编码基因、核糖体和转移 RNA。我们还提供了证据表明，两种同物种的火蚁线粒体基因组之间存在重组。最后，我们讨论了使用完整的线粒体基因组序列来改进系统发育估计的潜在方法。
蚂蚁线粒体基因组是研究膜翅目线粒体基因组结构、进化和系统发育的重要补充。我们进一步证明，在许多分类学水平（包括同物种和同属）进行采样对于深入了解线粒体基因组进化是有用且重要的。我们还讨论了如何通过考虑分支之间的非平稳和非均匀进化来帮助改进线粒体基因组在系统发育分析中的应用。
