Leber B, Hemleben V
Nucleic Acids Res. 1979 Nov 10;7(5):1263-81. doi: 10.1093/nar/7.5.1263.
Digestion of plant chromatin from Brassica pekinensis and Matthiola incana with staphylococcus nuclease leads to a DNA repeat of 175 plus or minus 8 and a core size of 140 base pairs. DNase I digestion results in multiples of 10 bases. Ribosomal RNN genes were studied as a model system for active plant chromatin because of their great redundancy and their high transcriptional activity in growing and differentiating tissues. The actively transcribed genes were identified by nascent RNA of ribosomal origin still attached to its matrix DNA. Hybridization techniques were used to demonstrate that even transcriptionally active gene sequences are present in nuclease generated chromatin subunits. Comparison of the DNase I kinetics of chromatin digestion with the amount of ribosomal RNA genes which is available for hybridization at the given times indicated that ribosomal RNA genes are digested, but not preferentially degraded by DNase I.
用葡萄球菌核酸酶消化白菜和紫罗兰的植物染色质，会产生175±8的DNA重复序列和140个碱基对的核心大小。DNase I消化产生10个碱基的倍数。核糖体RNN基因因其高度冗余以及在生长和分化组织中的高转录活性，被作为活性植物染色质的模型系统进行研究。通过仍附着于其基质DNA的核糖体来源的新生RNA来鉴定活跃转录的基因。杂交技术被用于证明即使是转录活性基因序列也存在于核酸酶产生的染色质亚基中。将染色质消化的DNase I动力学与在给定时间可用于杂交的核糖体RNA基因数量进行比较，结果表明核糖体RNA基因会被DNase I消化，但不会被优先降解。
