Positive and relaxed selection associated with flight evolution and loss in insect transcriptomes.
Positive and relaxed selection associated with flight evolution and loss in insect transcriptomes.
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DOI：
10.1093/gigascience/gix073
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发表时间：
2017-10-01
期刊：
影响因子：
9.2
通讯作者：
Zhou X
中科院分区：
文献类型：
--
作者：
Mitterboeck TF;Liu S;Adamowicz SJ;Fu J;Zhang R;Song W;Meusemann K;Zhou X
动力飞行的进化是促进昆虫成功的一项重大创新。此前，对鸟类、蝙蝠和昆虫的研究已经在与飞行进化和/或丧失相关的能量相关基因中检测到了不同选择方案的分子特征。在这里，使用从昆虫转录组获得的1000多个核和线粒体蛋白质编码基因的DNA序列，我们进行了更广泛的探索，哪些基因类别显示积极和宽松的选择在飞行的起源，以及与多个独立的损失的飞行。我们检测到一些类别的核基因更经常下积极选择的血统，导致有翼昆虫（Pterygota），有关分解代谢过程，如蛋白酶，以及剪接相关基因。飞行损失与剪接基因中的松弛选择特征相关，反映了飞行进化的结果。类似于以前的研究中的飞行损失在各种动物类群，我们观察到一贯较高的nonsynthesous同义替换比率在线粒体基因的不会飞的血统，指示放松选择能量相关的基因。虽然没有检测到氧化磷酸化基因被选择与飞行的起源具体，他们最常被检测到的正选择在全变态（完全变态）的昆虫相比，其他昆虫谱系。这项研究支持一些收敛与飞行能力相关的基因特异性选择压力，和探索性分析提供了一些新的见解基因类别可能与昆虫的飞行的增益和损失。
The evolution of powered flight is a major innovation that has facilitated the success of insects. Previously, studies of birds, bats, and insects have detected molecular signatures of differing selection regimes in energy-related genes associated with flight evolution and/or loss. Here, using DNA sequences from more than 1000 nuclear and mitochondrial protein-coding genes obtained from insect transcriptomes, we conduct a broader exploration of which gene categories display positive and relaxed selection at the origin of flight as well as with multiple independent losses of flight. We detected a number of categories of nuclear genes more often under positive selection in the lineage leading to the winged insects (Pterygota), related to catabolic processes such as proteases, as well as splicing-related genes. Flight loss was associated with relaxed selection signatures in splicing genes, mirroring the results for flight evolution. Similar to previous studies of flight loss in various animal taxa, we observed consistently higher nonsynonymous-to-synonymous substitution ratios in mitochondrial genes of flightless lineages, indicative of relaxed selection in energy-related genes. While oxidative phosphorylation genes were not detected as being under selection with the origin of flight specifically, they were most often detected as being under positive selection in holometabolous (complete metamorphosis) insects as compared with other insect lineages. This study supports some convergence in gene-specific selection pressures associated with flight ability, and the exploratory analysis provided some new insights into gene categories potentially associated with the gain and loss of flight in insects.