Simon J A, Sutton C A, Lobell R B, Glaser R L, Lis J T
Cell. 1985 Apr;40(4):805-17. doi: 10.1016/0092-8674(85)90340-x.
Modified Drosophila heat shock genes were introduced into the germ line by P element transformation. The genes were altered such that several factors could be tested for their influence upon chromosome puffing. Deletion of promoter sequences upstream of position -73 of an hsp70-IacZ hybrid gene was sufficient to abolish puffing. Analysis of progressive 5' deletions defines a 16 bp interval that contains sequences required for both heat-induced puffing and gene expression. An internal deletion of the hsp70-IacZ gene that reduces the transcript size from 9 kb to 0.8 kb results in a dramatic reduction in puff size. The chromosomal insertion sites of 26 variant hsp70 or hsp26 genes fail to influence puffing greatly with one marked exception. This transformant possesses an insert that fails to puff and exhibits a tissue-restricted pattern of expression. These results indicate that variation in either promoter strength or transcript length have profound effects on puffing.
通过P因子转化将修饰的果蝇热休克基因导入生殖系。对这些基因进行了改造，以便能够测试几种因素对染色体疏松的影响。hsp70-IacZ杂交基因-73位点上游启动子序列的缺失足以消除疏松现象。对渐进性5'端缺失的分析确定了一个16bp的区间，该区间包含热诱导疏松和基因表达所需的序列。hsp70-IacZ基因的内部缺失使转录本大小从9kb减少到0.8kb，导致疏松大小显著减小。26个变体hsp70或hsp26基因的染色体插入位点对疏松的影响不大，但有一个明显的例外。这个转化体具有一个不发生疏松且表现出组织限制性表达模式的插入片段。这些结果表明，启动子强度或转录本长度的变化对疏松有深远影响。
