Figure 2

Northern blot analysis of rasGEFM expression in parental and mutant strains. (A) Total RNA was extracted from AX2 cells developed in suspension for 0 to 9 hours or on filters. In the latter case the cells were harvested at mound (12 hours), first finger (16 hours) and preculminant (20 hours) stages. The membrane was hybridized to a radiolabelled rasGEFM specific probe (probe a) corresponding to bp 760–1518 of the cDNA clone and to the actin gene used as a loading control. (B) Total RNA was extracted from different developmental Dictyostelium mutants starved in shaking suspension up to 6 hours. LW6 (G protein β subunit minus), HSB1 (PIA ts-mutant, defective in the G-protein adenylyl cyclase activation) and HSB50 (mutant blocked at mound stage).