Rozenblatt S, Lavi S, Singer M F, Winocour E
J Virol. 1973 Sep;12(3):501-10. doi: 10.1128/JVI.12.3.501-510.1973.
A preparation of serially passaged simian virus 40 (SV40) DNA, in which at least 66% of the molecules contain covalently linked cellular DNA sequences, was digested to completion with the Hemophilus influenzae restriction endonuclease. Polyacrylamide gel electrophoresis of the digest showed that the majority of the cleavage products migrated as nine classes of fragments, each class defined by a particular molecular weight. These classes of fragments differ in molecular weight from the fragments produced by the action of the same enzyme on plaque-purified virus DNA. Three classes of fragments were present in less than equimolar amounts relative to the original DNA. The remaining six classes of fragments each contain more than one fragment per original DNA molecule. DNA-DNA hybridization analysis (using the filter method) of the isolated cleavage products demonstrated the presence of highly reiterated cell DNA sequences in two of the nine classes of fragments. A third class of fragments hybridized with high efficiency only to serially passaged SV40 DNA; the level of hybridization to plaque-purified virus DNA was low and there was essentially no hybridization with cell DNA immobilized on filters. It is suggested that this class of fragments contains unique host sequences. It was estimated that at least 27% of the sequences in the substituted SV40 DNA molecules studied are host sequences. The majority of these are probably of the nonreiterated type.
一种经连续传代的猴病毒40（SV40）DNA制剂，其中至少66%的分子含有共价连接的细胞DNA序列，用流感嗜血杆菌限制性内切酶完全消化。消化产物的聚丙烯酰胺凝胶电泳显示，大多数切割产物迁移为九类片段，每一类由特定分子量定义。这些片段类别在分子量上与同一酶作用于噬斑纯化病毒DNA产生的片段不同。相对于原始DNA，三类片段的含量低于等摩尔量。其余六类片段每一个原始DNA分子都包含不止一个片段。对分离的切割产物进行DNA-DNA杂交分析（使用滤膜法）表明，九类片段中的两类含有高度重复的细胞DNA序列。第三类片段仅与连续传代的SV40 DNA高效杂交；与噬斑纯化病毒DNA的杂交水平较低，与固定在滤膜上的细胞DNA基本没有杂交。提示这类片段含有独特的宿主序列。据估计，在所研究的取代SV40 DNA分子中，至少27%的序列是宿主序列。其中大多数可能是非重复类型的。
