McClure M A, Johnson M S, Doolittle R F
Proc Natl Acad Sci U S A. 1987 May;84(9):2693-7. doi: 10.1073/pnas.84.9.2693.
An anomalous sequence in certain lentiviruses was found to be related to a region in a completely different part of the simian retrovirus type I (SRV-I) and its close relative, the hamster intracisternal A particle (IAP-H18). The segment is not present in the human immunodeficiency virus (HIV), which is also a lentivirus, nor is it found in any one of a dozen other retroviruses whose sequences have been reported. These observations imply that a horizontal transfer of newly acquired genetic information has taken place between an SRV-I-type virus and one of the lentivirus type, and that this event occurred more recently than did the divergence of members of this latter group and HIV. Comparison of the viral nucleic acid sequences that encode these segments revealed the presence of imperfect direct nucleotide repeats resembling the retroviral endonuclease cleavage sites at the 5' and 3' ends of these regions.
在某些慢病毒中发现的一个异常序列与猴逆转录病毒I型(SRV-I)及其近亲仓鼠脑内A颗粒(IAP-H18)完全不同部位的一个区域相关。该片段在同样属于慢病毒的人类免疫缺陷病毒(HIV)中不存在,在已报道序列的其他十几种逆转录病毒中也未发现。这些观察结果表明,新获得的遗传信息在SRV-I型病毒和一种慢病毒之间发生了水平转移,而且这一事件发生的时间比后一组病毒成员与HIV的分化时间更近。对编码这些片段的病毒核酸序列进行比较后发现,在这些区域的5'和3'端存在类似逆转录病毒内切酶切割位点的不完全直接核苷酸重复序列。