Sommer H, Bonas U, Saedler H
Max-Planck-Institut für Züchtungsforschung, Köln, Federal Republic of Germany.
Mol Gen Genet. 1988 Jan;211(1):49-55. doi: 10.1007/BF00338392.
Four solid-colour revertants were isolated from the highly variegated niv-53::Tam1 mutant, in which the transposable element Tam1 is integrated in the promoter region of the chalcone synthase (chs) gene. DNA sequence analysis revealed that in all four lines the Tam1 element was deleted together with flanking nucleotides of the chs promoter. In one case the TATA box of the chs gene was removed resulting in extremely low expression of the gene, and initiation of transcription occurring at a new position. The other three deletions defined a sequence motif (TAC-CAT) which is apparently required for maximal gene expression. Thus transposable elements seem to be useful for probing gene structure, in this case the signal structure in the promoter region, by virtue of imprecise excision.
从高度杂色的niv-53::Tam1突变体中分离出四个纯色回复体，其中转座因子Tam1整合在查尔酮合酶（chs）基因的启动子区域。DNA序列分析表明，在所有四个株系中，Tam1元件与其chs启动子的侧翼核苷酸一起被删除。在一个案例中，chs基因的TATA框被去除，导致该基因的表达极低，转录起始发生在一个新位置。另外三个缺失定义了一个序列基序（TAC-CAT），这显然是基因最大表达所必需的。因此，转座因子似乎有助于通过不精确切除来探测基因结构，在这种情况下是启动子区域的信号结构。
