关于缓慢复性（“单一”）DNA的异质性

On the heterogeneity of the slow reassociating ("unique") DNA.

作者信息

Ivanov I G, Markov G G

出版信息

Mol Cell Biochem. 1978 Jun 28;20(2):111-8. doi: 10.1007/BF00241389.

Abstract

The slow reassociating fraction of mouse DNA ("unique DNA"), when allowed to reassociate in 0.14 M sodoum phosphate buffer at 50 degrees C showed a biphasic melting curve with a transition at 78--80 degrees C. On the basis of this feature, the slow reassociating DNA was separated preparatively into two fractions: "unique DNA" I and II. Their duplexes showed differences with respect to thermal stability, S1 nuclease resistance and rate of reassociation. About one third of the sequences in each fraction were fraction-specific. The conclusion was drawn that for "unique DNA" I these should be the low repetitive or single copy related sequences (multigene families) and for "unique DNA" II--the unrelated single copy sequences or recent families of low repetitive not yet diverged sequences.

摘要

小鼠DNA的缓慢复性部分（“单一DNA”），当在0.14M磷酸钠缓冲液中于50℃复性时，呈现出一条双相解链曲线，其转变温度在78 - 80℃。基于这一特征，缓慢复性的DNA被制备性地分离成两个部分：“单一DNA”I和II。它们的双链在热稳定性、对S1核酸酶的抗性和复性速率方面存在差异。每个部分中约三分之一的序列是部分特异性的。得出的结论是，对于“单一DNA”I，这些应该是低重复或单拷贝相关序列（多基因家族），而对于“单一DNA”II，则是不相关的单拷贝序列或低重复且尚未分化的近期家族序列。