Spinelli G, Ciliberto G
Nucleic Acids Res. 1985 Nov 25;13(22):8065-81. doi: 10.1093/nar/13.22.8065.
The SV40 enhancer microinjected into the nuclei of X. laevis oocytes is able to activate transcription about 100-fold when cloned upstream of the SV40 early promoter region or about 10-fold regardless of its orientation when located at a long distance from a test gene (bacterial chloramphenicol acetyl transferase). This effect is qualitatively and quantitatively similar to that observed when analogous constructions were transfected into mammalian cells. Making use of a direct labelling technique for the analysis of the chromatin structure we could show that the SV40 enhancer region in the microinjected plasmids is particularly accessible to cleavage with MNase or DNAse I. Single sites in the 72 bp repeats have been mapped at the nucleotide level.
将SV40增强子显微注射到非洲爪蟾卵母细胞核中，当克隆到SV40早期启动子区域上游时，它能够激活转录约100倍；当位于距测试基因（细菌氯霉素乙酰转移酶）较远的位置时，无论其方向如何，它都能激活转录约10倍。这种效应在定性和定量上与将类似构建体转染到哺乳动物细胞中时观察到的效应相似。利用直接标记技术分析染色质结构，我们可以表明，显微注射质粒中的SV40增强子区域特别容易被微球菌核酸酶或DNA酶I切割。72 bp重复序列中的单个位点已在核苷酸水平上进行了定位。
