Fig. 5.
Effects of DIF-1 and DIF-2 on chemotaxis and stalk cell formation in Ax2, gst4–, and gst4OE. (A–C) Ax2 (A), gst4– (B), and gst4OE (C) cells were starved for 6 h, and cell droplets were placed on PB agar containing 3 mM caffeine (control) plus 10 nM DIF-1 or DIF-2. Cells were assayed for chemotaxis toward the indicated doses of cAMP (10 cell droplets were examined for each cAMP concentration). Data are the mean±SD (bars) for triplicate samples. *, P<0.05 versus control cells. (D) Ax2, gst4–, and gst4OE cells were incubated for 20 h with cAMP (5 mM), washed free of the additive, and further incubated for 28 h with DMSO (0.2%) or DIF-1 (10 and 100 nM) or DIF-2 (10 and 100 nM). Stalk cell formation was assessed by phase-contrast microscopy, and the mean values±SD (bars) from four independent experiments are presented. No significant difference in stalk cell formation was noted between the strains.