Molecular mechanism of cell differentiation in mammalian cells.

为了鉴定参与小鼠Friend细胞分化的细胞内因子，首先通过细胞融合实验分析分化过程。实验表明，这一过程是两种基本不同的诱导细胞内反应协同作用的结果。一种反应是在DNA损伤后诱导的，另一种反应是由典型的红细胞诱导剂如DMSO或HMBA诱导的。我们寻找了假定的反式作用分化诱导因子，并检测到与这些反应相对应的两种蛋白质因子（DIF-1和DIF-II）。部分纯化的因子在引入未分化细胞时触发红系分化，条件是reciprent细胞已通过诱导两种反应中的任一种而增强。并对胚胎癌细胞的分化机制进行了探讨。

In order to identify intracellular factors involved in differentiation of mouse Friend cells, the differentiation process was first analyzed by cell fusion experiments. The experiments suggested that the process is a synergistic results of two basically different inducible intracellular reactions. One reaction is induced following damage to DNA and the other reaction is induced by typical erythroid inducing agents such as DMSO or HMBA. We searched for the putative transacting differentiation inducing factors and detected two proteinaceous factors (DIF-i and DIF-II) corresponding to these reactions. The partially purified factors triggered erythroid differentiation when introduced into undifferentiated cells, provided that the reciprent cells had been potentiated by the induction of either one of the two reactions. Mechanism of differentiation fo embryonal carcinoma cells was also studied.