Northeast Forestry University, College of Wildlife Resources, Harbin 150040, China.
Northeast Forestry University, College of Wildlife Resources, Harbin 150040, China; State Forestry Administration Detecting Center of Wildlife Resources, Harbin 150040, China.
Gene. 2018 Oct 20;674:8-14. doi: 10.1016/j.gene.2018.06.066. Epub 2018 Jun 22.
The bird mitogenome is generally considered to have a conservative genome size, consistent gene content, and similar gene order. As more mitogenomes are sequenced, mitochondrial (mt) gene rearrangements have been frequently identified among diverse birds. Within two genera (Bubo and Strix) of typical owls (Strigidae, Strigiformes), the rearrangement of the mt gene has been a subject of debate. In the current study, we first sequenced the whole mitogenomes of S. uralensis and B. scandiaca and resequenced the entire mitogenome of B. bubo. By combining our data with previously sequenced mitogenomes in Strigidae, we examined the mt gene rearrangements in the family and attempted to reconstruct the evolutionary progression of these rearrangements. The mitogenomes were then used to review the phylogenies of Strigidae. Most mitogenomes exhibited the ancestral gene order (A) in Strigidae. The ancestral gene order in the previously published mitogenome of B. bubo was found to be incorrect. We determined the mt gene order (the duplicate tRNA-CR, B) and discovered two additional mt gene orders (the duplicate tRNA-CR and CR, C and D) in the Bubo and Strix genera. Gene order B was likely derived from A by a tandem duplication of the region spanning from tRNA to CR. The other two modified gene orders, C and D, were likely derived from B by further degenerations or deletions of one copy of specific duplicated genes. We also preliminarily reconstructed the evolutionary progression of mt gene rearrangements and discussed maintenance of the duplicated CR in the genera. Additionally, the phylogenetic trees based on the mitogenomes supported the division of Strigidae into three subfamilies: Ninoxinae + (Surniinae + Striginae). Within the Striginae clade, the four genera formed a phylogenetic relationship: Otus + (Asio + (Bubo + Strix)). This suggests that Otus firstly diverges in their evolutionary history, and Bubo and Strix show a close relationship. B. bubo, B. blakistoni and B. scandiaca form a clade should be considered members of the same genus. The well-supported topology obtained in our Bayesian inference (BI) and maximum likelihood (ML) analyses of Strigid mitogenomes suggests that these genomes are informative for constructing phylogenetic relationships.
鸟类的线粒体基因组通常被认为具有保守的基因组大小、一致的基因内容和相似的基因排列。随着越来越多的线粒体基因组被测序，不同鸟类之间的线粒体（mt）基因重排经常被发现。在两个典型的猫头鹰（Strigidae，Strigiformes）属（Bubo 和 Strix）中，mt 基因的重排一直是一个争论的话题。在本研究中，我们首先对 S. uralensis 和 B. scandiaca 的整个线粒体基因组进行了测序，并对 B. bubo 的整个线粒体基因组进行了重新测序。通过将我们的数据与 Strigidae 中以前测序的线粒体基因组相结合，我们检查了该科的 mt 基因重排，并试图重建这些重排的进化进程。然后使用这些线粒体基因组来审查 Strigidae 的系统发育。大多数线粒体基因组表现出 Strigidae 的祖先基因排列（A）。以前发表的 B. bubo 线粒体基因组中的祖先基因排列被发现是不正确的。我们确定了 mt 基因排列（重复的 tRNA-CR，B），并在 Bubo 和 Strix 属中发现了另外两种 mt 基因排列（重复的 tRNA-CR 和 CR，C 和 D）。基因排列 B 可能是通过 tRNA 到 CR 区域的串联重复从 A 衍生而来的。另外两种修饰的基因排列 C 和 D 可能是通过特定重复基因的一个拷贝的进一步退化或缺失从 B 衍生而来的。我们还初步重建了 mt 基因重排的进化进程，并讨论了在属中重复 CR 的维持。此外，基于线粒体基因组的系统发育树支持 Strigidae 分为三个亚科：Ninoxinae + (Surniinae + Striginae)。在 Striginae 分支中，四个属形成了一个系统发育关系：Otus + (Asio + (Bubo + Strix))。这表明 Otus 在其进化历史上首先分化，而 Bubo 和 Strix 表现出密切的关系。B. bubo、B. blakistoni 和 B. scandiaca 形成一个分支，应被视为同一属的成员。我们对 Strigid 线粒体基因组进行的贝叶斯推断（BI）和最大似然（ML）分析获得的良好支持拓扑结构表明，这些基因组对于构建系统发育关系是有信息的。
