Avian reticuloendotheliosis virus: characterization of the high-molecular-weight viral RNA in transforming and helper virus populations
Avian reticuloendotheliosis virus: characterization of the high-molecular-weight viral RNA in transforming and helper virus populations
复制标题
禽网状内皮增生病毒：转化病毒和辅助病毒群体中高分子量病毒 RNA 的表征
作者：
M. Gonda;N. Rice;R. Gilden
网状内皮增生病毒 T 株 (REV-T) 是一种 C 型逆转录病毒，已知可转化禽类成纤维细胞、脾细胞和骨髓细胞，并在幼鸡中产生剧毒的网状内皮增生。通过变性凝胶电泳和电子显微镜对 REV-T 高分子量 RNA 的分析揭示了至少两类分子的存在。 CH3HgOH 凝胶中出现的一类单体长度为 9.3 千碱基 (kb)；在轻度变性条件下的电子显微镜扩散中，它以典型的逆转录病毒二聚体形式存在，单体长度为 8.8 +/- 0.7 kb。第二类也以二聚体形式存在，在 CH3HgOH 凝胶中单体长度为 5.7 kb。与 REVA-A 32P 标记的互补 DNA 杂交揭示了第三种尺寸类别的分子 (4.7 kb)，这些分子在电子显微镜涂片中无法从 5.7 kb 类别中分离出来，并且在变性凝胶中与鸡 28S rRNA 共迁移。据报道，用 REV-T 感染犬胸腺细胞系后产生的非转化病毒中仅发现了 9.3 kb 类型。因此，REV-T 似乎与鼠科动物和猫科动物肉瘤病毒以及禽类急性白血病病毒相似，因为它由非转化辅助病毒基因组和负责致癌性的缺陷基因组组成。我们之前的结果表明，在 REV-T 和未感染的鸡细胞 DNA 中存在一些犬科病毒产生的病毒中未发现的核苷酸序列（S. Simek 和 N. Rice，J. Virol. 33：320--329，1980）。在本报告中，我们通过与高度特异性的 32P 标记互补 DNA 杂交表明，REV-T 特异性序列存在于 5.7 kb 基因组内。由于从犬源性病毒基因组合成的 32P 标记互补 DNA 与所有三类 RNA 杂交，我们得出结论，5.7 kb 基因组是推定辅助病毒中发现的一些序列与 REV-T 特异的一些序列之间的重组体。与上述其他致癌病毒一样，这些特定序列似乎源自宿主 DNA。
Reticuloendotheliosis virus strain T (REV-T) is a type C retrovirus known to transform avian fibroblasts, spleen cells, and bone marrow cells and to produce virulent reticuloendotheliosis in young chicks. Analysis of REV-T high-molecular-weight RNA by electrophoresis in denaturing gels and by electron microscopy revealed the presence of at least two classes of molecules. One class appeared in CH3HgOH gels to have a monomer length of 9.3 kilobases (kb); in electron microscopic spreads under mildly denaturing conditions, it existed as a typical retrovirus dimer, having a monomer length of 8.8 +/- 0.7 kb. The second class also existed as a dimer, with a monomer length of 5.7 kb in CH3HgOH gels. Hybridization with REVA-A 32P-labeled complementary DNA revealed a third size class of molecules (4.7 kb), which were not resolvable from the 5.7-kb class in electron microscope spreads and which comigrated with chicken 28S rRNA in denaturing gels. Only the 9.3-kb class was found in the reportedly nontransforming virus produced after infection of canine thymus cell line with REV-T. Thus, REV-T appears to be similar to the murine and feline sarcoma viruses and the avian acute leukemia viruses in that it consists of a nontransforming helper virus genome and a defective genome responsible for oncogenicity. Our previous results demonstrated the presence in REV-T and in uninfected chicken cellular DNA of some nucleotide sequences not found in virus produced by the canine line (S. Simek and N. Rice, J. Virol. 33:320--329, 1980). In this report we show by hybridization with highly specific 32P-labeled complementary DNAs that REV-T-specific sequences exist within the 5.7-kb genome. Since 32P-labeled complementary DNA synthesized from the canine-derived virus genome hybridized with all three classes of RNAs, we conclude that the 5.7-kb genome is a recombinant between some sequences found in the putative helper and some sequences specific to REV-T. As with the other oncogenic viruses mentioned above, these specific sequences appear to be derived from host DNA.