Battula N, Temin H M
Proc Natl Acad Sci U S A. 1977 Jan;74(1):281-5. doi: 10.1073/pnas.74.1.281.
The infectious DNAs of a number of avian leukosis-sarcoma and reticuloendotheliosis viruses were digested with six nucleotide-specific restriction endonucleases, and the digests were tested for infectivity. All of the enzymes inactivated the viral infectivities except for EcoRI, which did not inactivate the infectivity of the DNA of two of the reticuloendotheliosis viruses, spleen necrosis and chick syncytial viruses. The infectious DNA of spleen necrosis virus after digestion with EcoRI had a buoyant density in CsCl solution greater than the density of the high-molecular-weight infectious viral DNA. The infectious EcoRI-digested spleen necrosis virus DNA from chronically infected chicken cells was uniform in size, 10 megadaltons, which indicated a single site of integration. The infectious EcoRI-digested spleen necrosis virus DNA from acutely infected cells was heterogeneous in size, ranging from 8-14 megadaltons, which indicated multiple sites of integration. These results are consistent with the hypothesis that cells that integrate infectious spleen necrosis virus DNA at a single site survive and multiply, whereas cells that integrate infectious viral DNA at additional sites either die or selectively lose or inactivate the DNA in the additional sites.
用六种核苷酸特异性限制性内切酶消化了多种禽白血病 - 肉瘤病毒和网状内皮组织增生症病毒的感染性DNA，并对消化产物进行了感染性测试。除EcoRI外，所有酶均使病毒感染性失活，EcoRI不会使两种网状内皮组织增生症病毒（脾坏死病毒和鸡合胞体病毒）的DNA感染性失活。用EcoRI消化后的脾坏死病毒感染性DNA在CsCl溶液中的浮力密度大于高分子量感染性病毒DNA的密度。来自慢性感染鸡细胞的经EcoRI消化的脾坏死病毒感染性DNA大小均匀，为10兆道尔顿，这表明有一个整合位点。来自急性感染细胞的经EcoRI消化的脾坏死病毒感染性DNA大小不均一，范围为8 - 14兆道尔顿，这表明有多个整合位点。这些结果与以下假设一致：在单个位点整合感染性脾坏死病毒DNA的细胞存活并增殖，而在其他位点整合感染性病毒DNA的细胞要么死亡，要么选择性地丢失或使其他位点的DNA失活。
