髓样细胞特异性SETD4基因敲除小鼠的构建与鉴定

目的　利用FLP/FRT、Cre/Loxp重组酶系统构建并鉴定髓样细胞特异性SETD4基因敲除小鼠，为深入研究SETD4的生物学功能奠定基础。 方法　将引进的Setd4flox/+小鼠自交，筛选出子代基因型为Setd4flox/flox的小鼠；与FLP小鼠交配，得到Setd4fl/+/flp小鼠；然后分别与C57BL/6小鼠交配去除FLP酶，筛选出Setd4fl/+小鼠；与Lyz2-Cre小鼠交配，筛选出Setd4fl/+/Lyz2-Cre小鼠；将得到的Setd4fl/+和Setd4fl/+/Lyz2-Cre小鼠交配，筛选出Setd4-/-/Lyz2-Cre小鼠，即髓样细胞特异性SETD4基因敲除小鼠。利用PCR技术鉴定小鼠基因型；实时荧光定量PCR技术检测小鼠腹腔巨噬细胞及肝组织中SETD4 的mRNA表达水平验证敲除情况。 结果　髓样细胞特异性SETD4基因敲除小鼠腹腔巨噬细胞中SETD4 mRNA水平较野生型小鼠显著降低；而在肝组织中无显著差异。 结论　利用FLP/FRT、Cre/Loxp系统成功构建髓样细胞特异性SETD4基因敲除小鼠，为后续的功能学研究提供了动物模型。

Establishment and identification of myeloid cell-specific SETD4 knockout mice

Objective　To elucidate the function of SETD4, we established myeloid cell-specific SETD4 knockout mice. 　Methods　Setd4flox/+ mice were inbred to obtain Setd4flox/flox mice, which then bred with FLP mice to obtain the Setd4fl/+/flp mice. After crossing with C57BL/6 mice, Setd4fl/+ mice were obtained, while Setd4fl/+/Lyz2-Cre were obtained after crossing with Lyz2-Cre mice. And then Setd4-/-/Lyz2-Cre mice were generated by mating Setd4fl/+/Lyz2-Cre with Setd4fl/+ mice. PCR was used to identify the genotype of offspring. The mRNA level of SETD4 in peritoneal macrophages and liver were detected by quantitative real time PCR to confirm the knockout efficiency.　Result　The mRNA expression of SETD4 in peritoneal macrophages of myeloid cell-specific SETD4 knockout mice was significantly lower than the wildtype mice, while no significant difference could be detected in the liver.　Conclusion　Based on FLP/FRT、Cre/Loxp recombination system, myeloid cell-specific SETD4 knockout mice were successfully established for further research.