Molecular adaptation in plant hemoglobin, a duplicated gene involved in plant-bacteria symbiosis
Molecular adaptation in plant hemoglobin, a duplicated gene involved in plant-bacteria symbiosis
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DOI：
10.1007/s00239-004-2632-9
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发表时间：
2004-09-01
影响因子：
3.9
通讯作者：
Galtier, N
中科院分区：
文献类型：
--
作者：
Guldner, E;Godelle, B;Galtier, N
被子植物中血红蛋白基因家族的进化历史是不寻常的，因为它涉及两种已知的可能产生分子适应的机制：基因复制和物种间相互作用。在能够与固氮细菌实现共生的植物中，2 类血红蛋白在根瘤中以高浓度表达，并且似乎是实现和调节共生交换的关键因素。在这项研究中，我们利用 DNA 序列进化的密码子模型，目的是确定驱动该基因进化的选择力的性质。我们的结果表明，适应性进化发生在复制事件（功能分歧）之后的一段时间内，并且 2 类血红蛋白中出现了与共生功能的获得相关的选择压力的变化。
The evolutionary history of the hemoglobin gene family in angiosperms is unusual in that it involves two mechanisms known for potentially generating molecular adaptation: gene duplication and among-species interaction. In plants able to achieve symbiosis with nitrogen-fixing bacteria, class 2 hemoglobin is expressed at high concentrations in nodules and appears to be a key factor for the achievement and regulation of the symbiotic exchange. In this study, we make use of codon models of DNA sequence evolution with the goal of determining the nature of the selective forces which have driven the evolution of this gene. Our results suggest that adaptive evolution occurred during the period of time following the duplication event (functional divergence) and that a change in the selective pressures arose in class 2 hemoglobin in relation to the acquisition of a symbiotic function.