DIF-resistant expression of a prespore-specific gene in Dictyostelium in vitro development.

In submerged culture, the prespore-specific gene, D19, of Dictyostelium discoideum was found to be expressed in the early stages of development, even in the presence of 1 nM of DIF-1 (stalk differentiation inducing factor). This concentration of DIF-1 later caused the degradation of the previously accumulated D19 mRNA concomitant with the induction of the prestalk-specific genes ecmA/ecmB and eventually 85% of cells differentiated into stalk cells. These results suggest that prespore differentiation occurs at least transiently even in the presence of DIF-1.