摘要
用ＤＮＡ复性动力学方法克隆到一个水稻（ＯｒｙｚａｓａｔｉｖａＬ．）中度重复ＤＮＡ顺序。不同限制性内切酶消化和Ｓｏｕｔｈｅｒｎ杂交分析显示，这段重复ＤＮＡ顺序以串联加散布的形式存在于水稻基因组中；序列分析表明在它内部含有一个典型的植物启动子序列ＴＧＴＡＴＡＡＡＴＡ；以ｐＲＲＤ３克隆片段作探针，对水稻３４个品种进行拷贝数测定，在野生稻与栽培稻、籼稻与粳稻之间均存在拷贝数上的明显差异；对ＡＡ基因组不同亚型水稻ＤＮＡ进行Ｓｏｕｔｈｅｒｎ杂交分析，得到基因组亚型特异的杂交带谱，说明该重复顺序是研究水稻进化和分类的一个有用探针。
A moderately repetitive DNA sequence from rice (Oryza sativa L.) has been cloned by the method of DNA renaturation kinetics. Different restriction enzymes digestion and Southern hybridization indicated that this sequence was organized in tandem array and dispersed in rice genome. There was a perfect plant promoter element TGTATAAATA within the sequence. Copy number of the cloned repetitive DNA sequence pRRD3 was determined within 34 varieties of Oryza, detectable differences were found between wild rice and cultivated rice as well as subspecies indica and japonica. Southern blot analysis on different AA genome type rice DNA showed genome subtypespecific hybridization pattern, suggesting that the repetitive DNA sequence pRRD3 is a useful probe to study the evolution and classification of rice.
