劳氏肉瘤病毒感染的胚胎成纤维细胞染色质中前病毒序列的分布
Distribution of proviral sequences in chromatin of embryonic fibroblasts infected by Rous sarcoma virus.
作者信息
Pantazis P, Schulz R A, Chirikjian J G, Papas T S
出版信息
Proc Natl Acad Sci U S A. 1981 May;78(5):2669-72. doi: 10.1073/pnas.78.5.2669.
Sheared chromatin prepared from chicken embryo fibroblasts and fibroblasts transformed by exogenous Rous sarcoma virus (Schmidt--Ruppin strain D) was separated by rate sedimentation on glycerol gradients into two components: fast-migrating (heavy chromatin fraction) and slow-migrating (light chromatin fraction). DNAs extracted from these fractions were assayed for proviral sequences by molecular hybridization using DNA complementary to the viral sequences. In uninfected cells, the endogenous complementary sequences were found to be equally distributed between heavy and light fractions. However, the newly integrated exogenous proviral sequences were found mostly in the light chromatin fraction in the transformed cells. Additionally, the light fraction was more sensitive to DNase I digestion and contains more material melting at low temperatures when compared with the heavy fraction. The results show that (i) distribution of endogenous proviral sequences is independent of chromatin conformation, and (ii) most of the newly acquired exogenous sequences are integrated within the host's chromatin fraction that exhibits properties of euchromatin. Because chromatin fragmentation and fractionation is accomplished without digestion with degrading enzymes, the chromatin fractions enriched in exogenous sequences remain intact and thus are suitable for further studies.
从鸡胚成纤维细胞以及由外源性劳氏肉瘤病毒（施密特-鲁平D株）转化的成纤维细胞制备的剪切染色质，通过在甘油梯度上的速率沉降分离为两个组分：快速迁移组分（重染色质部分）和慢速迁移组分（轻染色质部分）。使用与病毒序列互补的DNA通过分子杂交对从这些组分中提取的DNA进行前病毒序列检测。在未感染的细胞中，内源性互补序列在重、轻组分中分布均等。然而，在转化细胞中，新整合的外源性前病毒序列大多存在于轻染色质部分。此外，与重组分相比，轻组分对DNase I消化更敏感，并且含有更多在低温下熔化的物质。结果表明：（i）内源性前病毒序列的分布与染色质构象无关；（ii）大多数新获得的外源性序列整合在宿主染色质部分中，该部分表现出常染色质的特性。由于染色质片段化和分级分离是在不使用降解酶消化的情况下完成的，富含外源性序列的染色质组分保持完整，因此适合进一步研究。
Zotero 插件