Fig. 4. Dictyostelium Hip1r-null cells produce round, calcofluor-positive spores that have SP70 within the spore coats. (A-D) Wild-type and Hip1r-null spores were harvested, stained with the cellulose-staining dye calcofluor and viewed by phase-contrast or fluorescence microscopy. Wild-type (WT) spores are elliptical in morphology, whereas Hip1r-null spores (Hip1r-) are round. Bar, 5 µm. (E-T) Hip1r-null cells secrete outer-layer spore coat proteins. Wild-type (WT) and Hip1r-null spores were harvested, fixed and stained with an antibody against an outer spore coat protein, SP70, and viewed by DIC (E-H and M-P) or fluorescence (I-L and Q-T) microscopy. Bar, 5 µm.