Oct-4是一种哺乳动物早期胚胎中特异表达的转录因子,它与细胞多能性的维持有关.异源Oct-4基因在早期胚胎中的表达模式尚不明确.构建了一个以完整的牛Oct-4调控区指导GFP表达的转基因结构pOct-4(p)-GFP,通过单精子注射的方法将其导入猪、兔和小鼠的受精卵中,分析其在胚胎发育过程中的表达情况.结果显示:牛Oct-4启动子驱动的GFP基因在3个物种的2-细胞胚胎就已经开始表达,在囊胚期表达加强且只特异表达于内细胞团中,而不表达于滋养层.研究表明:牛的Oct-4启动子在其他物种中也具有表达活性,异源性Oct-4启动子在不同物种的早期胚胎中具有相似的表达模式.
The transcription factor Oct-4 is expressed specifically in mammalian preimplantation embryos and its function is related to the maintenance of embryonic stem cell pluripotency. The functional role of the heterogenous expression of Oct-4 remains unclear however. A GFP reporter construct, pOct-4(p)-GFP was generated, containing the upstream regulatory regions of bovine Oct-4 gene and its expression pattern was evaluated in the developing embryos of mouse, pig and rabbit following intracytoplasmic sperm injection. GFP fluorescence was visible early at the 2-cell stage and then became stronger in the blastocysts of all three species. However, the distribution of the GFP signals was restricted to the cells of inner cell mass and no fluorescence was detectable in trophectoderm cells. These results suggest that the bovine Oct-4 promoter is functional and that its embryonic expression activity is similar in different mammalian species.