REVERSIBLE METHYLATION AND INACTIVATION OF MARKER GENES IN SEQUENTIALLY TRANSFORMED TOBACCO PLANTS
REVERSIBLE METHYLATION AND INACTIVATION OF MARKER GENES IN SEQUENTIALLY TRANSFORMED TOBACCO PLANTS
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DOI：
10.1002/j.1460-2075.1989.tb03421.x
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发表时间：
1989-03-01
期刊：
影响因子：
11.4
通讯作者：
MATZKE, AJM
中科院分区：
文献类型：
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作者：
MATZKE, MA;PRIMIG, M;MATZKE, AJM
使用编码不同选择和筛选标记的两种T-DNA进行连续转化步骤后获得了双重转化的烟草植物：T-DNA-I编码卡那霉素抗性和胭脂碱合成酶; T-DNA-II编码潮霉素抗性和章鱼碱合成酶。对双转化植株后代中选择和筛选标记基因的遗传分析表明，T-DNA-I基因的表达常常受到抑制。这种抑制可能与这些基因启动子的甲基化有关。令人惊讶的是，T-DNA-I基因的甲基化和失活仅发生在含有两种T-DNA的植物中：当自交或回交产生仅含有T-DNA-I的后代时，该T-DNA上的基因表达恢复，相应的启动子部分或完全去甲基化。这些结果表明，一个T-DNA的存在可能会影响同一基因组中第二个未连接的T-DNA上基因的甲基化状态和表达。
Doubly transformed tobacco plants were obtained following sequential transformation steps using two T-DNAs encoding different selection and screening markers: T-DNA-I encoded kanamycin resistance and nopaline synthase; T-DNA-II encoded hygromycin resistance and octopine synthase. A genetic analysis of the inheritance of the selection and screening marker genes in progeny of the doubly transformed plants revealed that the expression of T-DNA-I genes was often suppressed. This suppression could be correlated with methylation in the promoters of these genes. Surprisingly, both the methylation and inactivation of T-DNA-I genes occurred only in plants containing both T-DNAs: when self-fertilization or backcrossing produced progeny containing only T-DNA-I, expression of the genes on this T-DNA was restored and the corresponding promoters were partially or completely demethylated. These results indicated that the presence of one T-DNA could affect the state of methylation and expression of genes on a second, unlinked T-DNA in the same genome.