Dowton Mark, Cameron Stephen L, Dowavic Jessica I, Austin Andy D, Whiting Michael F
Centre for Biomedical Sciences, School of Biological Sciences, University of Wollongong, NSW, Australia.
Mol Biol Evol. 2009 Jul;26(7):1607-17. doi: 10.1093/molbev/msp072. Epub 2009 Apr 9.
We present entire sequences of two hymenopteran mitochondrial genomes and the major portion of three others. We combined these data with nine previously sequenced hymenopteran mitochondrial genomes. This allowed us to infer and analyze the evolution of the 67 mitochondrial gene rearrangements so far found in this order. All of these involve tRNA genes, whereas four also involve larger (protein-coding or ribosomal RNA) genes. We find that the vast majority of mitochondrial gene rearrangements are independently derived. A maximum of four of these rearrangements represent shared, derived organizations, whereas three are convergently derived. The remaining mitochondrial gene rearrangements represent new mitochondrial genome organizations. These data are consistent with the proposal that there are an enormous number of alternative mitochondrial genome organizations possible and that mitochondrial genome organization is, for the most part, selectively neutral. Nevertheless, some mitochondrial genes appear less mobile than others. Genes close to the noncoding region are generally more mobile but only marginally so. Some mitochondrial genes rearrange in a pattern consistent with the duplication/random loss model, but more mitochondrial genes move in a pattern inconsistent with this model. An increased rate of mitochondrial gene rearrangement is not tightly associated with the evolution of parasitism. Although parasitic lineages tend to have more mitochondrial gene rearrangements than nonparasitic lineages, there are exceptions (e.g., Orussus and Schlettererius). It is likely that only a small proportion of the total number of mitochondrial gene rearrangements that have occurred during the evolution of the Hymenoptera have been sampled in the present study.
我们展示了两个膜翅目线粒体基因组的完整序列以及另外三个基因组的主要部分。我们将这些数据与九个先前测序的膜翅目线粒体基因组相结合。这使我们能够推断并分析迄今为止在该目昆虫中发现的67种线粒体基因重排的进化情况。所有这些重排都涉及tRNA基因，而其中四种还涉及更大的（蛋白质编码或核糖体RNA）基因。我们发现绝大多数线粒体基因重排是独立发生的。这些重排中最多有四种代表共享的、衍生的组织形式，而三种是趋同衍生的。其余的线粒体基因重排代表新的线粒体基因组组织形式。这些数据与以下观点一致：可能存在大量的线粒体基因组组织形式，并且线粒体基因组组织在很大程度上是选择性中性的。然而，一些线粒体基因似乎比其他基因移动性更低。靠近非编码区的基因通常移动性更强，但只是略微如此。一些线粒体基因以与复制/随机丢失模型一致的模式重排，但更多的线粒体基因以与该模型不一致的模式移动。线粒体基因重排速率的增加与寄生现象的进化没有紧密关联。尽管寄生谱系往往比非寄生谱系有更多的线粒体基因重排，但也有例外（如Orussus和Schlettererius）。在本研究中，可能仅采样了膜翅目进化过程中发生的线粒体基因重排总数的一小部分。
