Caparroz Renato, Rocha Amanda V, Cabanne Gustavo S, Tubaro Pablo, Aleixo Alexandre, Lemmon Emily M, Lemmon Alan R
Departamento de Genética e Morfologia, Laboratório de Genética e Biodiversidade, Instituto de Ciências Biológicas, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, Distrito Federal, CEP 70910-900, Brazil.
División de Ornitología, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Ciudad de Buenos Aires, Argentina.
Mol Biol Rep. 2018 Jun;45(3):279-285. doi: 10.1007/s11033-018-4160-5. Epub 2018 Feb 17.
At least four mitogenome arrangements occur in Passeriformes and differences among them are derived from an initial tandem duplication involving a segment containing the control region (CR), followed by loss or reduction of some parts of this segment. However, it is still unclear how often duplication events have occurred in this bird order. In this study, the mitogenomes from two species of Neotropical passerines (Sicalis olivascens and Lepidocolaptes angustirostris) with different gene arrangements were first determined. We also estimated how often duplication events occurred in Passeriformes and if the two CR copies demonstrate a pattern of concerted evolution in Sylvioidea. One tissue sample for each species was used to obtain the mitogenomes as a byproduct using next generation sequencing. The evolutionary history of mitogenome rearrangements was reconstructed mapping these characters onto a mitogenome Bayesian phylogenetic tree of Passeriformes. Finally, we performed a Bayesian analysis for both CRs from some Sylvioidea species in order to evaluate the evolutionary process involving these two copies. Both mitogenomes described comprise 2 rRNAs, 22 tRNAs, 13 protein-codon genes and the CR. However, S. olivascens has 16,768 bp showing the ancestral avian arrangement, while L. angustirostris has 16,973 bp and the remnant CR2 arrangement. Both species showed the expected gene order compared to their closest relatives. The ancestral state reconstruction suggesting at least six independent duplication events followed by partial deletions or loss of one copy in some lineages. Our results also provide evidence that both CRs in some Sylvioidea species seem to be maintained in an apparently functional state, perhaps by concerted evolution, and that this mechanism may be important for the evolution of the bird mitogenome.
雀形目至少存在四种线粒体基因组排列方式，它们之间的差异源于最初涉及包含控制区（CR）的片段的串联重复，随后该片段的某些部分发生丢失或缩减。然而，目前仍不清楚这种鸟类目级分类中重复事件发生的频率。在本研究中，首次测定了两种具有不同基因排列的新热带雀形目鸟类（橄榄绿雀鹀和窄嘴啄木鸟）的线粒体基因组。我们还估计了雀形目中重复事件发生的频率，以及在莺总科中两个CR拷贝是否表现出协同进化模式。每个物种使用一个组织样本，通过下一代测序作为副产品获得线粒体基因组。通过将这些特征映射到雀形目的线粒体基因组贝叶斯系统发育树上，重建了线粒体基因组重排的进化历史。最后，我们对一些莺总科物种的两个CR进行了贝叶斯分析，以评估涉及这两个拷贝的进化过程。所描述的两个线粒体基因组均包含2个rRNA、22个tRNA、13个蛋白质编码基因和CR。然而，橄榄绿雀鹀的线粒体基因组有16,768 bp，呈现出鸟类祖先的排列方式，而窄嘴啄木鸟的线粒体基因组有16,973 bp，具有残余的CR2排列方式。与它们最近的亲属相比，这两个物种都显示出预期的基因顺序。祖先状态重建表明至少有六次独立的重复事件，随后在一些谱系中一个拷贝发生部分缺失或丢失。我们的结果还提供了证据，表明在一些莺总科物种中，两个CR似乎都通过协同进化维持在明显的功能状态，并且这种机制可能对鸟类线粒体基因组的进化很重要。
