Bartman T, Murasko D M, Sieck T G, Turturro A, Hart R, Blank K J
Graduate Program in Molecular Biology and Genetics, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Virology. 1994 Aug 15;203(1):1-7. doi: 10.1006/viro.1994.1448.
Although most inbred strains of mice contain endogenous retroviral sequences, these sequences are usually not capable of producing infectious retroviruses. In some cases, the retroviral sequences are small fragments of viral genomes. In a few cases the sequences for complete retroviruses exist, but contain small defects which prevent the production of infectious virus. While the ability of reversions of these defects to produce retroviruses has been studied by site-directed mutagenesis and chemical-mediated mutagenesis, the presence of spontaneously occurring reversions has not been completely evaluated. We characterized an infectious ecotropic retrovirus spontaneously expressed in aged DBA/2 mice, which carries the complete but defective Emv-3. Although this endogenously produced retrovirus was related to the endogenous Emv-3 sequence, it had undergone recombination with another retroviral sequence to correct the defect which resided in the gag of Emv-3. Thus, recombination of endogenous ecotropic retroviral sequences may be a mechanism to produce infectious retroviruses in adult animals that contributes to pathologic disease.
尽管大多数近交系小鼠都含有内源性逆转录病毒序列，但这些序列通常无法产生具有传染性的逆转录病毒。在某些情况下，逆转录病毒序列是病毒基因组的小片段。在少数情况下，完整逆转录病毒的序列存在，但含有小缺陷，这些缺陷阻止了传染性病毒的产生。虽然通过定点诱变和化学介导的诱变研究了这些缺陷的回复产生逆转录病毒的能力，但自发发生的回复的存在尚未得到全面评估。我们鉴定了一种在老龄DBA/2小鼠中自发表达的具有传染性的亲嗜性逆转录病毒，它携带完整但有缺陷的Emv-3。尽管这种内源性产生的逆转录病毒与内源性Emv-3序列相关，但它已与另一种逆转录病毒序列发生重组，以纠正Emv-3 gag中存在的缺陷。因此，内源性亲嗜性逆转录病毒序列的重组可能是成年动物中产生传染性逆转录病毒的一种机制，这会导致病理性疾病。
