Enucleation blocks the morphological response of glioblasts to glia maturation factor.

Culture glioblasts obtained from rat fetuses were enucleated with cytochalasin B. The glia maturation factor stimulated the morphological differentiation of nucleated but not enucleated cells. In contrast, 8-bromo-cyclic AMP stimulated the morphological differentiation of both nucleated and enucleated cells. This distinction implies a difference in the mode of action of the two agents on cultured glioblasts, and suggests that an interaction between the nucleus and cytoplasm is required for expression of the morphological effect of the glia maturation factor.