Recombination systems represent a major breakthrough in the field of genetic model engineering. The Flp recombinases (Flp, Flpe, and Flpo) bind and cleave DNA Frt sites. We created a transgenic mouse strain ([Fsp1‐Flpo]) expressing the Flpo recombinase in fibroblasts. This strain was obtained by random insertion inside mouse zygotes after pronuclear injection. Flpo expression was placed under the control of the promoter of Fsp1 (fibroblast‐specific protein 1) gene, whose expression starts after gastrulation at Day 8.5 in cells of mesenchymal origin. We verified the correct expression and function of the Flpo enzyme by several ex vivo and in vivo approaches. The [Fsp1‐Flpo] strain represents a genuine tool to further target the recombination of transgenes with Frt sites specifically in cells of mesenchymal origin or with a fibroblastic phenotype.

中文翻译：

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Fsp1（成纤维细胞特异性蛋白1）-Flpo转基因小鼠品系的生成。

重组系统代表了遗传模型工程领域的重大突破。Flp重组酶（Flp，Flpe和Flpo）结合并切割DNA Frt位点。我们创建了一个在成纤维细胞中表达Flpo重组酶的转基因小鼠品系（[Fsp1-Flpo]）。该菌株是通过在原核注射后随机插入小鼠受精卵而获得的。Flpo表达被置于Fsp1启动子的控制之下（成纤维细胞特异性蛋白1）基因，其表达在第8.5天在胃间质起源的细胞中排胃后开始。我们通过几种离体和体内方法验证了Flpo酶的正确表达和功能。[Fsp1-Flpo]菌株代表了一种真正的工具，可进一步靶向具有Frt位点的转基因重组，特别是在间充质来源或成纤维细胞表型的细胞中。