INTRONS INCREASE TRANSCRIPTIONAL EFFICIENCY IN TRANSGENIC MICE
INTRONS INCREASE TRANSCRIPTIONAL EFFICIENCY IN TRANSGENIC MICE
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DOI：
10.1073/pnas.85.3.836
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发表时间：
1988-02-01
影响因子：
11.1
通讯作者：
PALMITER, RD
中科院分区：
文献类型：
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作者：
BRINSTER, RL;ALLEN, JM;PALMITER, RD
设计实验来测试内含子对转基因小鼠基因表达的影响。四对不同的基因构建体（除了每对中的一个成员缺乏所有内含子外）是相同的，在通过受精卵显微注射引入小鼠种系后，比较了 mRNA 的表达。分别在胎儿肝脏或胰腺中测定通过将小鼠金属硫蛋白I或大鼠弹性蛋白酶I启动子/增强子与大鼠生长激素基因融合而产生的两个嵌合基因的表达，而在胎儿肝脏中测定两个天然基因，即寡核苷酸标记的小鼠金属硫蛋白I基因和人β-珠蛋白基因。在每种情况下，含有内含子的构建体产生的 mRNA 平均多出 10 至 100 倍。此外，mRNA 水平与在分离的细胞核中测量的相对转录率成正比。然而，当转染培养细胞后测试两种基于小鼠金属硫蛋白 I 基因的构建体的表达时，几乎没有观察到差异。这些观察结果表明，内含子在促进显微注射基因的转录中发挥作用，并且这种作用可能仅在暴露于发育影响的基因上表现出来。
Experiments were designed to test the effect of introns on gene expression to transgenic mice. Four different pairs of gene constructs, which were identical except that one member of each pair lacked all introns, were compared for expression of mRNA after introduction into the murine germ line by microinjection of fertilized eggs. The expression of two chimeric genes, made by fusing either the mouse metallothionein I or the rat elastase I promoter/enhancer to the rat growth hormone gene, was assayed in fetal liver or pancreas, respectively, while two natural genes, an oligonucleotide-marked mouse metallothionein I gene and the human .beta.-globin gene, were assayed in fetal liver. In each case there was, on average 10- to 100-fold more mRNA produced from the intron-containing construct. Moreover, mRNA levels were proportional to the relative rates of transcription that were measured in isolated nuclei. However, when the expression of the two mouse metallothionein I gene-based constructs was tested after transfection into cultured cells, little difference was observed. These observations suggest that introns play a role in facilitating transcription of microinjected genes and that this effect may be manifest only on genes exposed to developmental influences.