Evidence for positive Darwinian selection on the hepcidin gene of Perciform and Pleuronectiform fishes
Evidence for positive Darwinian selection on the hepcidin gene of Perciform and Pleuronectiform fishes
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DOI：
10.1007/s11030-007-9066-4
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发表时间：
2007-08-01
影响因子：
3.8
通讯作者：
Verghese, Bindhu
中科院分区：
文献类型：
--
作者：
Padhi, Abinash;Verghese, Bindhu
铁调素是一种富含半胱氨酸的小肽，在抗微生物活性和维持脊椎动物体内铁稳态中起重要作用。在这里，我们报告的基本机制，保持高序列之间的hepcidin类似的鲈形和pleuronectiform鱼类的变体。与哺乳动物相反，基于最大可能性的密码子置换分析揭示，正达尔文选择（非同义到同义置换，ω> 1）是这些鱼的铁调素成熟肽区域中氨基酸置换速率加快的可能原因。将在某些位点引入正选择（ω> 1）的模型与不引入正选择（ω < 1）的模型进行比较，未能拒绝（p = 0）在percifom和pleuronectiform hepcidin的密码子位点中正选择的证据。鲈形目鱼类和鲽形目鱼类的这种肽的适应性进化可能是在宿主暴露于新的栖息地/环境时由病原体引导的。
Hepcidin is a small cysteine-rich peptide that plays an important role in antimicrobial activity and in maintaining iron homeostasis in vertebrates. Here we report on the underlying mechanism that maintains high sequence diversities among the hepcidin-like variants of perciform and pleuronectiform fishes. In contrast to mammals, maximum likelihood-based codon substitution analyses revealed that positive Darwinian selection (nonsynonymous to synonymous substitution, omega > 1) is the likely cause of accelerated rate of amino acid substitutions in the hepcidin mature peptide region of these fishes. Comparison of models incorporating positive selection (omega > 1) at certain sites with models not incorporating positive selection (omega < 1) failed to reject (p = 0) the evidence of positive selection among the codon sites of percifom and pleuronectiform hepcidin. The adaptive evolution of this peptide in perciform and pleuronectiform fishes might be directed by pathogens when the host is exposed to new habitats/environments.