Dimcheff D E, Krishnan M, Mindell D P
Department of Biology, University of Michigan, Ann Arbor, Michigan 48109-1079, USA.
J Virol. 2001 Feb;75(4):2002-9. doi: 10.1128/JVI.75.4.2002-2009.2001.
In a previous study, we found avian sarcoma and leukosis virus (ASLV) gag genes in 19 species of birds in the order Galliformes including all grouse and ptarmigan (Tetraoninae) surveyed. Our data suggested that retroviruses had been transmitted horizontally among some host species. To further investigate these elements, we sequenced a replication-defective retrovirus, here named tetraonine endogenous retrovirus (TERV), from Bonasa umbellus (ruffed grouse). This is the first report of a complete, replication-defective ASLV provirus sequence from any bird other than the domestic chicken. We found a replication-defective proviral sequence consisting of putative Gag and Env proteins flanked by long terminal repeats. Reverse transcription-PCR analysis showed that retroviral gag sequences closely related to TERV are transcribed, supporting the hypothesis that TERV is an active endogenous retrovirus. Phylogenetic analyses suggest that TERV may have arisen via recombination between different retroviral lineages infecting birds. Southern blotting using gag probes showed that TERV occurs in tetraonines but not in chickens or ducks, suggesting that integration occurred after the earliest phasianid divergences but prior to the radiation of tetraonine birds.
在之前的一项研究中，我们在鸡形目19种鸟类中发现了禽肉瘤和白血病病毒（ASLV）gag基因，这些鸟类包括所有被调查的松鸡和雷鸟（松鸡亚科）。我们的数据表明逆转录病毒在一些宿主物种之间进行了水平传播。为了进一步研究这些元件，我们从披肩榛鸡中测序了一种复制缺陷型逆转录病毒，在此命名为松鸡亚科内源性逆转录病毒（TERV）。这是除家鸡外任何鸟类中完整的、复制缺陷型ASLV前病毒序列的首次报道。我们发现了一个复制缺陷型前病毒序列，其由两侧带有长末端重复序列的假定Gag和Env蛋白组成。逆转录-聚合酶链反应分析表明，与TERV密切相关的逆转录病毒gag序列被转录，支持了TERV是一种活跃的内源性逆转录病毒的假说。系统发育分析表明，TERV可能是通过感染鸟类的不同逆转录病毒谱系之间的重组产生的。使用gag探针的Southern印迹分析表明，TERV存在于松鸡亚科鸟类中，但不存在于鸡或鸭中，这表明整合发生在最早的雉科分歧之后，但在松鸡亚科鸟类辐射之前。
