Climate-driven mitochondrial selection: A test in Australian songbirds
Climate-driven mitochondrial selection: A test in Australian songbirds
复制标题
DOI：
10.1111/mec.14488
复制
发表时间：
2018-02-01
影响因子：
4.9
通讯作者：
Pavlova, Alexandra
中科院分区：
文献类型：
--
作者：
Lamb, Annika Mae;Gan, Han Ming;Pavlova, Alexandra
栖息在不同环境中的种群之间的多样化选择可以促进物种内的谱系分化，并最终推动物种形成。线粒体基因组（有丝分裂基因组）编码氧化磷酸化（OXPHOS）系统的必需蛋白，并且可以是气候驱动选择的强靶标（即，与居住在不同的气候有关）。我们调查了更新世气候变化是否驱动了澳大利亚鸟类的线粒体选择和进化。首先，利用线粒体ND2基因的地理分析17鸣禽种，我们确定了线粒体分支（mitolineages）。其次，使用基于距离的冗余分析，我们测试了气候是否预测种内遗传差异的变化，超出了地理距离和地理位置的解释。第三，我们分析了41个完整的有丝分裂基因组序列，代表每个线粒体17个物种使用密码子模型的系统发育框架和生化方法，以确定信号的选择OXPHOS蛋白编码基因和测试的平行选择线粒体不同物种存在于类似的气候。在检查的17个种属中，13个种属具有多个线粒体谱系（范围：2 - 6）。气候是8个物种线粒体变异的重要预测因子。OXPHOS复合物I中至少有两个氨基酸的替换可以在两个物种的特定线粒体中的正选择下进化。蛋白质同源性建模显示其中一个在ND6蛋白通道的环区，另一个在ND5的功能关键螺旋HL区。这些发现要求直接测试线粒体蛋白候选物在气候相关选择中的功能和进化意义。
Diversifying selection between populations that inhabit different environments can promote lineage divergence within species and ultimately drive speciation. The mitochondrial genome (mitogenome) encodes essential proteins of the oxidative phosphorylation (OXPHOS) system and can be a strong target for climate-driven selection (i.e., associated with inhabiting different climates). We investigated whether Pleistocene climate changes drove mitochondrial selection and evolution within Australian birds. First, using phylogeographic analyses of the mitochondrial ND2 gene for 17 songbird species, we identified mitochondrial clades (mitolineages). Second, using distance-based redundancy analyses, we tested whether climate predicts variation in intraspecific genetic divergence beyond that explained by geographic distances and geographic position. Third, we analysed 41 complete mitogenome sequences representing each mitolineage of 17 species using codon models in a phylogenetic framework and a biochemical approach to identify signals of selection on OXPHOS protein-coding genes and test for parallel selection in mitolineages of different species existing in similar climates. Of 17 species examined, 13 had multiple mitolineages (range: 2-6). Climate was a significant predictor of mitochondrial variation in eight species. At least two amino acid replacements in OXPHOS complex I could have evolved under positive selection in specific mitolineages of two species. Protein homology modelling showed one of these to be in the loop region of the ND6 protein channel and the other in the functionally critical helix HL region of ND5. These findings call for direct tests of the functional and evolutionary significance of mitochondrial protein candidates for climate-associated selection.