Tsuei D, Pogo B G, Friend C
Proc Natl Acad Sci U S A. 1980 Oct;77(10):5769-73. doi: 10.1073/pnas.77.10.5769.
The properties of the virus synthesized by each of three morphologically different cell lines originating from DBA/2J fetal liver cells transformed by the anemic strain of Friend leukemia virus in vitro were analyzed. The cells of line G-1 are malignant in syngeneic DBA/2 mice, grow in suspension, and are erythroid in origin. Cells of lines G-2 and G-3 are adherent, are epithelial in appearance, and produce no tumors in DBA/2J mice. Higher reverse transcriptase activity was detected in the culture fluid of lines G-2 and G-3, although virus from G-1 cells was more leukemogenic. Differences were also found in the virion density and size of the viral genome. RNA from the virions produced by G-2 and G-3 cells sedimented at 75 S in a sucrose gradient; virion RNA from G-1 cells sedmiented at 60 S. However, when subjected to polyacrylamide gel electrophoresis, all three virus strains showed identical RNA subunits with an estimated molecular weight of 2.6 X 10(6). Analysis of virion proteins by slab gel electrophoresis showed differences in envelope protein (gp71) components but not in the major core protein (p30). The properties of these viruses are stable and remain unchanged after passage in 3T3 cells.
对由三种形态不同的细胞系合成的病毒特性进行了分析，这三种细胞系源自体外被贫血株弗氏白血病病毒转化的DBA/2J胎肝细胞。G-1系细胞在同基因DBA/2小鼠中具有恶性，悬浮生长，起源于红系。G-2和G-3系细胞贴壁，外观呈上皮样，在DBA/2J小鼠中不产生肿瘤。在G-2和G-3系的培养液中检测到较高的逆转录酶活性，尽管来自G-1细胞的病毒致白血病性更强。在病毒体密度和病毒基因组大小方面也发现了差异。G-2和G-3细胞产生的病毒体RNA在蔗糖梯度中沉降于75S；G-1细胞的病毒体RNA沉降于60S。然而，当进行聚丙烯酰胺凝胶电泳时，所有三种病毒株都显示出相同的RNA亚基，估计分子量为2.6×10(6)。通过平板凝胶电泳分析病毒体蛋白显示包膜蛋白（gp71）成分存在差异，但主要核心蛋白（p30）没有差异。这些病毒的特性稳定，在3T3细胞中传代后保持不变。
