Molecular mechanism of cell differentiation in mammalian cells.

为了确定小鼠Friend细胞分化的细胞内因素，首先通过细胞融合实验分析了小鼠Friend细胞的分化过程。实验表明，这一过程是两个基本不同的可诱导细胞内反应的协同结果。一个反应是在DNA损伤后引起的，另一个反应是由典型的红系诱导剂如DMSO或HMBA引起的。我们搜索了可能的转导分化诱导因子，并检测到了与这些反应相对应的两个蛋白质因子(DIF-I和DIF-II)。部分纯化的因子被引入未分化的细胞时会触发红系分化，前提是复发的细胞已经通过两种反应中的任何一种反应的诱导而增强。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.