Regulated expression of the Ren‐2 gene in transgenic mice derived from parental strains carrying only the Ren‐1 gene.
Regulated expression of the Ren‐2 gene in transgenic mice derived from parental strains carrying only the Ren‐1 gene.
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在源自仅携带 Ren-1 基因的亲本品系的转基因小鼠中，Ren-2 基因的表达受到调节。
作者：
D. Tronik;M. Dreyfus;C. Babinet;F. Rougeon
将编码小鼠颌下腺（SMG）肾素的Ren-2基因显微注射到仅携带Ren-1基因的小鼠受精卵的原核中。除了整个转录单位，注射的DNA含有2.5和3 kb的上游和下游侧翼序列，分别。获得了三个独立的转基因小鼠系;其中两个整合了一个Ren-2基因拷贝，最后一个在两个独立位点整合了五个和十一个拷贝。与整合的Ren-2拷贝数无关，所有转基因小鼠中Ren-2基因表达的模式与野生型动物中观察到的相同，其中Ren-1和Ren-2在1号染色体上紧密连锁。特别是，外源性Ren-2基因仅在肾脏和SMG中转录。在肾脏中，Ren-1和Ren-2 mRNA的水平相当，而在SMG中，Ren-2 mRNA的丰度至少是Ren-1 mRNA的100倍。此外，SMG中的Ren-2表达受到雄激素的正调控。在转基因小鼠和携带Ren-2基因的野生型小鼠之间仅观察到一个差异：转基因雌性SMG中Ren-2转录的基础水平低于双基因品系雌性。雄激素处理的转基因女性诱导SMG肾素mRNA的水平相同的转基因男性。这表明SMG肾素mRNA的基础水平取决于显微注射片段中不存在的顺式作用元件。
The Ren‐2 gene encoding the mouse submaxillary gland (SMG) renin was microinjected into the pronuclei of fertilized eggs from mice carrying only the Ren‐1 gene. In addition to the whole transcription unit, the injected DNA contained 2.5 and 3 kb of upstream and downstream flanking sequences, respectively. Three independent transgenic mice lines were obtained; two of them had integrated one copy of the Ren‐2 gene, the last one had integrated five and eleven copies at two independent sites. Independently of the number of Ren‐2 copies integrated, the pattern of Ren‐2 gene expression in all the transgenic mice was identical to that observed in wild‐type animals in which Ren‐1 and Ren‐2 are closely linked on chromosome 1. In particular, the exogenous Ren‐2 gene was only transcribed in the kidney and in the SMG. In the kidney, Ren‐1 and Ren‐2 mRNAs were present at a comparable level, whereas in the SMG Ren‐2 mRNA was at least 100‐fold more abundant than Ren‐1 mRNA. Moreover, Ren‐2 expression in the SMG was positively regulated by androgens. Only one difference between transgenic mice and wild‐type mice carrying the Ren‐2 gene has been observed: the basal level of Ren‐2 transcription in the SMG of transgenic females was lower than in two‐gene strain females. Androgen treatment of transgenic females induced SMG renin mRNA to a level identical to that of transgenic males. This suggests that the basal level of SMG renin mRNA is dependent upon cis‐acting elements which are not present in the microinjected fragment.