中文摘要：

在无血清条件下培养KES小鼠胚胎干细胞,研究LIF在无血清条件下对小鼠胚胎干细胞增殖及多能性维持的影响。联合使用小分子物质SU5402、PD184352和CHIR99021或单独使用LIF培养小鼠胚胎干细胞,检测无血清条件下LIF对小鼠胚胎干细胞自我更新能力和全能性的影响。结合使用极限稀释法培养KES细胞单克隆,统计不同培养体系下单克隆的形成率。结果显示：无血清条件下,单独使用LIF,不能维持小鼠胚胎干细胞的自我更新能力和全能性;使用含有3种小分子药物SU5402,PD184352和CHIR99021（3i）的无血清培养液可以维持小鼠胚胎干细胞的自我更新,传代60代以上仍可保持全能性;添加LIF的3i培养系统显著提高了小鼠胚胎干细胞的单克隆形成率。表明在无血清条件下,LIF不能单独维持小鼠胚胎干细胞的多能性。3i培养体系可以维持胚胎干细胞的全能性而不需要LIF;3i条件下,LIF可以显著促进胚胎干细胞体外增殖和单克隆形成。

英文摘要：

This paper studied the effect of LIF for mouse embryonic stem cell proliferation and the maintenance of pluripotency under serum-free conditions by a combination of two FGF4 pathway inhibitors SU5402,PD184352,and GSK3 pathway inhibitors CHIR99021,cultures KES mouse embryonic stem cells under serum-free conditions.Respectively,the research uses three different serum-free culture systems to culture mouse embryonic stem cells and to detect the cardinal markers of pluripotency under serum-free conditions.By limiting dilution to obtain monoclonal,the authors count the monoclonal formation rates of using the different culture systems.Under serum-free conditions,the single using of LIF makes the mouse embryonic stem cell differentiation.The serum-free culture medium containing three kinds of small molecule drugs SU5402,PD184352,and CHIR99021（3i） can maintain mouse embryonic stem cells self-renewal,and still can maintain the pluripotency after passage 60.It significantly increases the monoclonal formation rate of mouse embryonic stem cell when containing LIF in 3i culture system.In serum-free conditions,LIF can not maintain the pluripotency of embryonic stem cells alone.3i culture system can maintain the pluripotency of embryonic stem cells without LIF.In 3i system,LIF can significantly promote the proliferation and monoclonal formation of embryonic stem cells.