Lineage-Specific Expansion of IFIT Gene Family: An Insight into Coevolution with IFN Gene Family
Lineage-Specific Expansion of IFIT Gene Family: An Insight into Coevolution with IFN Gene Family
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IFIT 基因家族的谱系特异性扩展：与 IFN 基因家族共同进化的见解
DOI：
10.1371/journal.pone.0066859
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发表时间：
2013-06-20
期刊：
影响因子：
3.7
通讯作者：
Gui, Jian-Fang
中科院分区：
文献类型：
--
作者：
Liu, Ying;Zhang, Yi-Bing;Gui, Jian-Fang
在哺乳动物中，IFIT（Interferon [IFN]-induced proteins with Tetratricopeptide Repeat [TPR] motifs）家族基因参与许多细胞和病毒过程，与哺乳动物的IFN应答密切相关。然而，对非哺乳动物IFIT基因知之甚少。在本研究中，IFIT基因在包括软骨象鲨在内的有颚脊椎动物的基因组数据库中被鉴定出来，但在文昌鱼、海鞘和橡子虫等非脊椎动物中却没有被鉴定出来，这表明IFIT基因家族起源于大约4.5亿年前的脊椎动物祖先。IFIT家族基因具有保守的基因结构和基因排列。系统发育分析表明，该基因家族通过谱系特异性和种特异性基因复制而扩展。有趣的是，IFN基因家族似乎有着共同的祖先和相似的进化机制; IFIT基因与IFN应答的功能联系在两个基因家族起源的早期就存在，如通过发现斑马鱼IFIT基因被鱼类IFN、poly（I：C）和两种转录因子IRF 3/IRF 7上调所证明的，可能是通过脊椎动物IFIT家族基因启动子内的IFN刺激应答元件（ISRE）。这些共同进化的特征创造了两个家族基因的功能关联，以实现共同的生物学过程，这可能是在脊椎动物进化过程中通过病毒感染选择的。我们的研究结果有助于理解脊椎动物IFN系统的进化。
In mammals, IFIT (Interferon [IFN]-induced proteins with Tetratricopeptide Repeat [TPR] motifs) family genes are involved in many cellular and viral processes, which are tightly related to mammalian IFN response. However, little is known about non-mammalian IFIT genes. In the present study, IFIT genes are identified in the genome databases from the jawed vertebrates including the cartilaginous elephant shark but not from non-vertebrates such as lancelet, sea squirt and acorn worm, suggesting that IFIT gene family originates from a vertebrate ancestor about 450 million years ago. IFIT family genes show conserved gene structure and gene arrangements. Phylogenetic analyses reveal that this gene family has expanded through lineage-specific and species-specific gene duplication. Interestingly, IFN gene family seem to share a common ancestor and a similar evolutionary mechanism; the function link of IFIT genes to IFN response is present early since the origin of both gene families, as evidenced by the finding that zebrafish IFIT genes are upregulated by fish IFNs, poly(I:C) and two transcription factors IRF3/IRF7, likely via the IFN-stimulated response elements (ISRE) within the promoters of vertebrate IFIT family genes. These coevolution features creates functional association of both family genes to fulfill a common biological process, which is likely selected by viral infection during evolution of vertebrates. Our results are helpful for understanding of evolution of vertebrate IFN system.