Shih T Y, Khoury G, Martin M A
Proc Natl Acad Sci U S A. 1973 Dec;70(12):3506-10. doi: 10.1073/pnas.70.12.3506.
Separated strands of simian virus 40 (SV40) DNA fragments were used in hybridization experiments to study the RNA transcribed by Escherichia coli RNA polymerase from the chromatin of cells transformed by SV40. The template activity of chromatin of the transformed cell line 11A8 (mouse-embryo cells) examined is about 17% that of purified DNA, suggesting that most of the chromatin DNA is repressed by chromosomal proteins. The SV40-specific RNA present in the RNA transcribed in vitro from 11A8 chromatin hybridizes specifically with the minus strand of SV40 DNA. Little or no reaction occurs with the plus strand of viral DNA. The SV40-specific RNA transcribed in vitro from chromatin of transformed cells shares sequences with the RNA produced during the early phase of SV40 lytic infection, and is similar to that present in the 11A8 cell line in vivo. Although the influence of chromosomal proteins on this pattern of transcription was not definitely determined, preliminary evidence indicates that an asymmetric pattern of transcription may also occur when 11A8 DNA is transcribed by E. coli RNA polymerase.
猿猴病毒40（SV40）DNA片段的单链用于杂交实验，以研究大肠杆菌RNA聚合酶从SV40转化细胞的染色质转录的RNA。所检测的转化细胞系11A8（小鼠胚胎细胞）染色质的模板活性约为纯化DNA的17%，这表明大部分染色质DNA被染色体蛋白抑制。从11A8染色质体外转录的RNA中存在的SV40特异性RNA与SV40 DNA的负链特异性杂交。与病毒DNA的正链几乎没有反应。从转化细胞染色质体外转录的SV40特异性RNA与SV40裂解感染早期产生的RNA具有相同序列，并且与体内11A8细胞系中存在的RNA相似。虽然染色体蛋白对这种转录模式的影响尚未明确确定，但初步证据表明，当大肠杆菌RNA聚合酶转录11A8 DNA时，也可能出现不对称转录模式。
