Scherdin U, Rhodes K, Breindl M
Department of Biology, San Diego State University, California 92182-0057.
J Virol. 1990 Feb;64(2):907-12. doi: 10.1128/JVI.64.2.907-912.1990.
We have analyzed the transcriptional activity of cellular target sequences for Moloney murine leukemia virus integration in mouse fibroblasts. At least five of the nine random, unselected integration target sequences studied showed direct evidence for transcriptional activity by hybridization to nuclear run-on transcripts prepared from uninfected cells. At least four of the sequences contained multiple recognition sites for several restriction enzymes that cut preferentially in CpG-rich islands, indicating integration into 5' or 3' ends or flanking regions of genes. Assuming that only a minor fraction (less than 20%) of the genome is transcribed in mammalian cells, we calculated the probability that this association of retroviral integration sites with transcribed sequences is due to chance to be very low (1.6 x 10(-2]. Thus, our results strongly suggest that transcriptionally active genome regions are preferred targets for retrovirus integration.
我们分析了莫洛尼鼠白血病病毒整合在小鼠成纤维细胞中的细胞靶序列的转录活性。在所研究的9个随机、未选择的整合靶序列中，至少有5个通过与未感染细胞制备的核延伸转录本杂交，显示出转录活性的直接证据。至少有4个序列含有几种限制酶的多个识别位点，这些酶优先在富含CpG的岛中切割，表明整合到基因的5'或3'末端或侧翼区域。假设在哺乳动物细胞中只有一小部分（不到20%）的基因组被转录，我们计算出逆转录病毒整合位点与转录序列的这种关联是由于偶然的概率非常低（1.6×10^(-2)）。因此，我们的结果强烈表明，转录活跃的基因组区域是逆转录病毒整合的首选靶标。
