Fig. 2

Developmental phenotype of the Pp gsk3⁻ mutant. A Cartoon highlighting differences between Pp and Dd development. B Fruiting bodies. Pp wild-type and gsk3⁻ cells were freed from bacteria and developed for 24 h on non-nutrient agar at 10⁶ cells/cm² and photographed. Bar: 0.5 mm. C Stalk cells. The fruiting bodies were picked up, deposited in 0.001% Calcofluor on a slide glass and photographed under phase contrast (Ph) and epifluorescence (Fl) Bar: 50 µm. D Spores. Prepared as in panel B, but photographed at higher magnification. Bar: 10 µm. E Sporulation efficiency. 4 × 10⁶ freshly harvested Pp amoebas were plated on 2 × 2 cm² nitrocellulose membranes, supported by non-nutrient agar. After completion of fruiting body formation, membranes were vortexed in 0.1% Triton-X100 and spore numbers were counted and expressed as percentage of plated cell numbers. Means and SD from 3 independent experiments. F Spore viability. Pp spores were harvested from 7-day-old fruiting bodies, treated for 10 min with 0.1% Triton-X100 to remove amoebas, counted and clonally plated on LP agar with E. coli. Emerging Pp colonies were counted after 4–5 days. Means and SD from 4 independent experiments. There were no significant differences between wild-type (WT) and gsk3⁻ cells in panels D and E (t test, P > 0.5)