In mice, the conditional knockout strategy using the Cre-loxP system is useful for various types of research. The Cre mouse line with progesterone receptor promoter (Pgr^Cre) has been widely used to produce specific uterine gene-deficient mice, but in the Cre line, endogenous Pgr gene is replaced by Cre recombinase gene, which makes the breeding of homozygous mice (Pgr^Cre/Cre) difficult because they are infertile. Yang et al. (2013, https://10.1016/j.cell.2013.04.017) reported the generation of another Pgr^iresCre mouse line that still has endogenous Pgr gene, and they inserted Cre recombinase downstream of the Pgr gene via an internal ribosome entry site (IRES). It is possible that this new Pgr^iresCre line would be useful for uterine research as the mice can be bred as homozygotes (Pgr^{iresCre/iresCre}). Herein, we confirmed the Pgr^iresCre mice effectively directed recombination in the female reproductive tract and was capable of genetic alteration in the endometrium that enables the studies of its uterine function. Our findings demonstrate that the new Pgr^iresCre mouse line is also useful for the generation of uterine-specific knockout mice. The findings using Pgr^iresCre mouse will contribute to the understanding of reproductive systems and diseases in humans and domestic animals.

中文翻译：

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黄体酮受体-ires-Cre 产生用于子宫研究的条件性基因敲除小鼠的效用

在小鼠中，使用 Cre-loxP 系统的条件敲除策略可用于各种类型的研究。具有孕激素受体启动子的Cre小鼠品系( Pgr ^Cre )已被广泛用于生产特异性子宫基因缺陷小鼠，但在Cre品系中，内源性Pgr基因被Cre重组酶基因所取代，使得纯合子小鼠的培育( Pgr ^Cre/Cre ) 很难，因为它们不育。杨等。(2013, https://10.1016/j.cell.2013.04.017) 报道了另一种仍然具有内源性Pgr基因的Pgr ^iresCre小鼠品系的产生，他们在Pgr下游插入了 Cre 重组酶基因通过内部核糖体进入位点 (IRES)。这种新的Pgr ^iresCre系可能对子宫研究有用，因为小鼠可以作为纯合子 ( Pgr ^{iresCre/iresCre} ) 进行繁殖。在此，我们证实Pgr ^iresCre小鼠在雌性生殖道中有效地定向重组，并且能够在子宫内膜中进行遗传改变，从而能够研究其子宫功能。我们的研究结果表明，新的Pgr ^iresCre小鼠品系也可用于产生子宫特异性基因敲除小鼠。使用Pgr ^{iresCre 的}结果老鼠将有助于了解人类和家畜的生殖系统和疾病。