酿酒酵母(Saccharomyces　cerevisiae)同源DNA片段的克隆

CLONING OF HOMOLOGOUS DNA FRAGMENTS FROM SACCHAROMYCES CEREVISIAE

利用作者克隆的酿酒酵母（Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｓｉａｅ）基因启动子片段Ｙ８为探针和菌落原位杂交方法，从构建的Ｓ．ｃｅｒｅｖｉｓｉａｅＹＮＮ２７基因组文库中共筛选到８个阳性克隆．根据这些克隆中插入片段大小和限制酶切结果，可将其划分为６种，分别命名为ＹＮ１～ＹＮ６．Ｓｏｕｔｈｅｒｎ杂交结果表明，这６种ＤＮＡ片段不仅能与６．５ｋｂ的全长Ｙ８探针杂交，而且均能与ＰｓｔⅠ酶切Ｙ８所得的３段ＤＮＡ探针（３．９ｋｂ，１．７ｋｂ，０．９ｋｂ）杂交．将６种ＤＮＡ片段的限制酶图谱与酿酒酵母中已知的多拷贝ＤＮＡ片段的限制酶图谱进行比较后发现。

By using the cloned gene promoter fragment Y8 as a probe and in situ colony hybridization,eight positive clones were isolated from the genomic library of Saccharomyces cerevisiae YNN27.These clones could be divided into 6 groups on the basis of length and restriction map of the inserted fragment in each clone and the six fragments were named YN1 to YN6,respetively.The results from Southern hybridization showed that all cloned fragments could hybridize not only with the whole Y8 fragment (6.5kb) but also with the three fragments from the PstⅠ digested Y8 fragment (3.9kb,1.7kb and 0.9kb).Comparison of restriction maps between there six clones and known multi copy elements suggested that these six fragments and Y8 belong to a new group of multi copy element.