中文摘要：

细胞分化是多细胞个体发育和干细胞实现功能活动的基本过程.作为诱导白色脂肪细胞分化的体外模型,小鼠3T3-L1前脂肪细胞系的定向分化过程由依赖于细胞周期特定时相（接触抑制期）的许可阶段和独立于细胞周期的执行阶段所组成.在接触抑制期,通过细胞代谢方式、细胞周期调控因子和细胞信号转导通路之间的相互作用,决定了各种染色质表观遗传修饰因子的活动,从而导致具备脂肪细胞分化潜能的染色质表观遗传修饰模式的形成.在随后的执行阶段,这种分化潜能被激素诱发,通过复杂的基因调控网络的动态活动,使各种控制脂肪细胞分化基因表达的转录因子按既定的分化时间表打开或者关闭,并决定相关的靶基因的表达,最终导致了脂肪细胞的形成.

英文摘要：

Cell differentiation is a basic process for development of multi-cellular organisms or functions of stem cells.By analyzing 3T3-L1 cell line,which is widely used as an in vitro model of adipocyte differentiation,it has been shown that the establishment of adipocyte differentiation of 3T3-L1 cells requires two stages：a licensing stage that depends on a particular cell-cycle stage,i.e.contact-inhibition stage,and then an execution stage that is independent on cell cycle stages.In the licensing stage,the activities of epigenetic factors are regulated by cellular metabolic states,cell-cycle regulators and cell signaling,and then result in particular epigenetic modifications to make an adipogenesis gene-expression program.During the execution stage,which is initiated by the induction of hormone cocktail,various transcription factors are dynamically expressed under the control of gene regulating network,and then result in adipocyte differentiation.