Transgene integration into the same chromosome location can produce alleles that express at a predictable level, or alleles that are differentially silenced
Transgene integration into the same chromosome location can produce alleles that express at a predictable level, or alleles that are differentially silenced
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DOI：
10.1101/gad.849600
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发表时间：
2000-11-15
影响因子：
10.5
通讯作者：
Ow, DW
中科院分区：
文献类型：
--
作者：
Day, CD;Lee, E;Ow, DW
为了控制植物中转基因表达的变异性，我们使用Cre-lax介导的重组将gus报告基因精确且可重复地插入不同的靶位点。选择用于分析的每个整合株系在指定的靶位点处具有转基因的单个拷贝。在任何给定的靶位点，近一半的插入给出了转基因表达的完整空间模式。然而，表达的绝对水平显示靶位点依赖性变化高达10倍。这证实了染色体位置可以影响基因表达水平的观点。一个意想不到的发现是，在任何给定的靶位点的近一半的插入未能给出转基因表达的完整空间模式。这些部分表达模式似乎可归因于基因沉默，因为低gus表达与DNA甲基化和低转录相关。甲基化对新整合的DNA是特异性的。在新插入的DNA之外没有发现甲基化变化。完整和部分表达状态都是减数分裂可遗传的。引入的转基因的沉默可以是在转化期间发生的随机事件。
In an effort to control the variability of transgene expression in plants, we used Cre-lax mediated recombination to insert a gus reporter gene precisely and reproducibly into different target loci. Each integrant line chosen for analysis harbors a single copy of the transgene at the designated target site. At any given target site, nearly half of the insertions give a full spatial pattern of transgene expression. The absolute level of expression, however, showed target site dependency that varied up to 10-fold. This substantiates the view that the chromosome position can affect the level of gene expression. An unexpected finding was that nearly half of the insertions at any given target site failed to give a full spatial pattern of transgene expression. These partial patterns of expression appear to be attributable to gene silencing, as low gus expression correlates with DNA methylation and low transcription. The methylation is specific for the newly integrated DNA. Methylation changes are not found outside of the newly inserted DNA. Both the full and the partial expression states are meiotically heritable. The silencing of the introduced transgenes may be a stochastic event that occurs during transformation.