Fig. 1.

Starvation in isotonic medium does not cause major alterations in Dictyostelium endocytic compartments. Dictyostelium wild-type cells grown in HL5 were starved in PB (hypotonic) or in StM (isotonic) medium for 2 h and then processed for immunofluorescence to detect p80 and H⁺-ATPase. Cells incubated in HL5 or starved in StM exhibited distinctive lysosomes (p80 positive and H⁺-ATPase positive; arrowheads) and postlysosomes (p80 positive and H⁺-ATPase negative; arrows). In contrast, cellular architecture was grossly altered when cells were starved in PB. The compartments positive for H⁺-ATPase but negative for p80 represent contractile vacuoles (pinheads). Scale bar, 5 μm.