Aguilar-Cordova E, Lebovitz R M, Lieberman M W
Department of Pathology, Baylor College of Medicine, Houston, Texas 77030.
Gene Expr. 1991;1(3):217-21.
S49 are mouse thymic lymphoma cells which do not express the two closely linked mouse metallothionein (MT) genes; however, previous studies demonstrated that treatment of S49 cells with chemical carcinogens or ultraviolet irradiation can activate these quiescent genes. To determine if activation of MT-I or MT-II in these variants is a result of cis-acting mutations, we amplified and sequenced the immediate 5' regions of 19 cadmium resistant S49 variants: MT-I+/MT-II-, MT-I-/MT-II+, MT-I+/MT-II+, and MT-I-/MT-II-. None of the variants contained mutations in the analyzed regions. Thus, the observed changes in MT expression must result from mutations at other sites or from non-mutational mechanisms.
S49是不表达两个紧密相连的小鼠金属硫蛋白(MT)基因的小鼠胸腺淋巴瘤细胞;然而,先前的研究表明,用化学致癌物或紫外线照射处理S49细胞可激活这些静止基因。为了确定这些变体中MT-I或MT-II的激活是否是顺式作用突变的结果,我们扩增并测序了19个镉抗性S49变体的紧邻5'区域:MT-I+/MT-II-、MT-I-/MT-II+、MT-I+/MT-II+和MT-I-/MT-II-。这些变体在分析区域均未发生突变。因此,观察到的MT表达变化必定是其他位点的突变或非突变机制导致的。