Prototype endogenous avian retroviruses of the genus Gallus.
Prototype endogenous avian retroviruses of the genus Gallus.
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DOI：
10.1099/vir.0.066852-0
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发表时间：
2014-09
期刊：
影响因子：
--
通讯作者：
M. Sacco;V. Nair
中科院分区：
文献类型：
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作者：
M. Sacco;V. Nair
古老的内源性逆转录病毒（ERV），称为内源性禽逆转录病毒（EAVs），存在于所有的鸡种。包括鸡，并且类似于现代的禽肉瘤和白血病病毒（ASLV）。EAVs包括几种不同的逆转录病毒，包括EAV-0，EAV-E51和EAV-HP，以及以前命名为鸡禽逆转录转座子（ART-CH）的推定成员。到目前为止，只有EAV-HP元件得到了很好的表征。在这里，我们通过对2011年原鸡基因组组装的克隆和数据挖掘来确定代表性EAV-0和EAV-E51前病毒的序列。尽管EAV-0元件主要在env区域缺失，但我们在G. gallus基因组和与先前命名为EAV-E33的EAV-E51相关克隆共享同一性的原型元件。对EAV-0、EAV-E51和EAV-E33的gag、pol和env基因序列进行系统发育分析，结果表明EAV-0与ASLV形成了3个不同的进化枝，其中EAV-0与ASLV是最后一个共同的祖先。EAV-E51进化枝与其他EAV或ASLV相比表现出最大程度的分歧，表明这些ERV代表了在很长一段时间内进化并整合到种系中的外源性逆转录病毒。此外，鸡和红原鸡EAV-E51序列之间的分歧程度表明，它们比其他EAVs更古老，可能是通过整合后积累的突变而分歧的。最后，我们表明ART-CH元件是包含EAV-E51和EAV-HP部分的嵌合缺陷ERV，而不是真正的反转录转座子。
Ancient endogenous retroviruses (ERVs), designated endogenous avian retrovirus (EAVs), are present in all Gallus spp. including the chicken, and resemble the modern avian sarcoma and leukosis viruses (ASLVs). The EAVs comprise several distinct retroviruses, including EAV-0, EAV-E51 and EAV-HP, as well as a putative member previously named the avian retrotransposon of chickens (ART-CH). Thus far, only the EAV-HP elements have been well characterized. Here, we determined sequences of representative EAV-0 and EAV-E51 proviruses by cloning and data mining of the 2011 assembly of the Gallus gallus genome. Although the EAV-0 elements are primarily deleted in the env region, we identified two complete EAV-0 env genes within the G. gallus genome and prototype elements sharing identity with an EAV-E51-related clone previously designated EAV-E33. Prototype EAV-0, EAV-E51 and EAV-E33 gag, pol and env gene sequences used for phylogenetic analysis of deduced proteins showed that the EAVs formed three distinct clades, with EAV-0 sharing the last common ancestor with the ASLVs. The EAV-E51 clade showed the greatest level of divergence compared with other EAVs or ASLVs, suggesting that these ERVs represented exogenous retroviruses that evolved and integrated into the germline over a long period of time. Moreover, the degree of divergence between the chicken and red jungle fowl EAV-E51 sequences suggested that they were more ancient than the other EAVs and may have diverged through mutations that accumulated post-integration. Finally, we showed that the ART-CH elements were chimeric defective ERVs comprising portions of EAV-E51 and EAV-HP rather than authentic retrotransposons.