【摘要】 本文对正常人淋巴细胞DNA的高重复顺序某些特性进行了研究。应用复性动力学方法分离了重复顺序并观察了复性后的稳定性。复性后的高重复顺序极易交织成网状结构,用低离子强度缓冲液透析,特别是除去磷酸根离子能使网状结构拆开,而镁离子对这种网状结构有稳定作用。用¹²⁵Ⅰ标记的高重复顺序用核酸酶S₁处理后热稳定性增加,但T_m 值仍低于天然DNA,表明复性后的高重复顺序除包含有单链片段外,碱基对中仍有错配。更多还原

【Abstract】 In the present paper,the highly repetitive sequences of human DNA have beenseparated by the reassociation kinetic method and the stability of these renaturedhighly repetitive sequences have been observed under different conditions.Some network structures can be formed during heat renaturation.Usually thesenetwork structures are stable in solutions of high ionic strength（0.4M phosphatebuffer）,but can be disintegrated if the ionic strength is lowered,especially phosphateions are removed by dialysis.Mg⁺⁺ions can stabilize these network structures.When highly repetitive sequences labelled with ¹²⁵I are digested with nucleaseS₁,their thermal stability can be improved but the T_m value is still seven degreeslower than native DNA,which is probably due to mispairing.更多还原