Quiroz Elvis, Marquardt Ryan M, Li Shu-Yun, Gruzdev Artiom, Cunefare David, Ganta Charan, Wu San-Pin, Lydon John P, DeMayo Francesco J
Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
Gene Editing and Mouse Model Core Facility, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
Biol Reprod. 2025 Jul 13;113(1):83-96. doi: 10.1093/biolre/ioaf090.
The Cre/loxP system is widely used for site-specific genetic manipulation in mice. The PgrCre mouse model, where Cre recombinase is driven by the progesterone receptor promoter, is commonly used for gene ablation in Pgr-positive uterine cells. However, the PgrCre is active in the neonatal uterus and does not allow temporal control. To enhance the functionality of the PgrCre mouse, we generated and characterized an inducible PgriCreERT2 mouse, in which iCreERT2 is inserted downstream of the endogenous Pgr promoter. PgriCreERT2 mice crossed with Rosa26-CAG-LSL-Sun1-sfGFP-myc reporter mice demonstrated tamoxifen-dependent recombination in uterine stromal fibroblasts and a subset of epithelial cells. Tamoxifen-induced ablation of PGR expression was accomplished by crossing PgriCreERT2 mice with the Pgrflox/flox mice. Resulting PgriCreERT2/Pgr:flox and Pgrflox/flox mice were treated with tamoxifen or oil vehicle daily for 3 days and assayed for fertility 1 month after treatment. Tamoxifen-treated PgriCreERT2/Pgr:flox mice exhibited implantation failure, dysregulation of uterine epithelial and stromal cell proliferation, and loss of decidualization response with no impact on ovulation or embryo transport. A 6-month breading trial demonstrated that 4/6 tamoxifen-treated PgriCreERT2/Pgr:flox mice were completely infertile, and the remaining 2/6 delivered only three total pups each near the end of the trial. In contrast, tamoxifen-treated Cre-negative females were fertile with normal uterine receptivity compared to vehicle controls, indicating that tamoxifen administration with a month-long recovery period did not impair pregnancy. Together, these data demonstrate the utility of this inducible PgriCreERT2 mouse model for spatiotemporally controlled gene ablation in Pgr-positive cells of the uterus.
Cre/loxP系统广泛用于小鼠的位点特异性基因操作。PgrCre小鼠模型中，Cre重组酶由孕酮受体启动子驱动，常用于Pgr阳性子宫细胞中的基因敲除。然而，PgrCre在新生子宫中具有活性，无法实现时间控制。为增强PgrCre小鼠的功能，我们构建并鉴定了一种可诱导的PgriCreERT2小鼠，其中iCreERT2插入到内源性Pgr启动子下游。将PgriCreERT2小鼠与Rosa26-CAG-LSL-Sun1-sfGFP-myc报告基因小鼠杂交，结果显示在子宫基质成纤维细胞和一部分上皮细胞中存在他莫昔芬依赖性重组。通过将PgriCreERT2小鼠与Pgrflox/flox小鼠杂交，实现了他莫昔芬诱导的PGR表达缺失。对所得的PgriCreERT2/Pgr:flox和Pgrflox/flox小鼠每天给予他莫昔芬或油性载体，持续3天，并在治疗后1个月检测生育能力。用他莫昔芬处理的PgriCreERT2/Pgr:flox小鼠表现出着床失败、子宫上皮和基质细胞增殖失调以及蜕膜反应丧失，对排卵或胚胎运输无影响。一项为期6个月的繁殖试验表明，4/6用他莫昔芬处理的PgriCreERT2/Pgr:flox小鼠完全不育，其余2/6在试验接近尾声时各自仅产下3只幼崽。相比之下，与载体对照组相比，用他莫昔芬处理的Cre阴性雌性小鼠具有正常的子宫接受性且可育，这表明给予他莫昔芬并经过为期1个月的恢复期不会损害妊娠。总之，这些数据证明了这种可诱导的PgriCreERT2小鼠模型在子宫Pgr阳性细胞中进行时空控制基因敲除的实用性。
