中文摘要：

目的：检测BRCA1及其剪接异构体BRCA1△11b在P19及人胚胎干细胞分化过程中的表达。方法：全反式维甲酸诱导P19细胞的分化,提取不同时间点RNA,运用RT-PCR,Real-time PCR分别检测P19细胞及人胚胎干细胞分化过程中BRCA1及其剪接异构体BRCA1△11b的表达。结果：未分化P19细胞在全反式维甲酸诱导下聚集形成拟胚体。在P19细胞拟胚体形成过程中,BRCA1△11b表达水平迅速降低,而BRCA1的表达则随P19细胞分化发生相反的变化,BRCA1表达水平迅速升高。在人胚胎细胞分化过程中,BRCA1基因同样发生选择性剪接的转换,由未分化时BRCA1△11b为主要剪接产物转换为拟胚体形成时BRCA1表达占优势。结论：BRCA1及其选择性剪接异构体BRCA1△11b在P19细胞及人胚胎干细胞分化过程中均发生选择性剪接的转换,BRCA1基因的选择性剪接可能在胚胎干细胞的分化过程中发挥重要作用。

英文摘要：

Objective： To examine whether alternative splicing of BRCA1 and BRCA1△11b occurs during P19 cell and human embryoid stem（hES） cell differentiation.Methods： All trans-retinoic acid（at-RA） was used to induce P19 cell differentiation.Total RNA was extracted at different time point during P19 cell differentiation.Reverse transcription（RT） polymerase chain reaction（PCR） and quantitative real-time PCR was used to assess BRCA1 and BRCA1△11b expression in P19 cells and hES cells.Results： The expression level of BRCA1△11b decreased but BRCA1 increased during the P19 and hES cell differentiation.Conclusion： An alternative splicing from BRCA1△11b transcript to BRCA1 transcript occurs during the EB（Embryoid Body） stages of both P19 cell and hES cell.