Figure 3. Rare incompatible cells segregate from the majority but eventually rejoin the population and produce spores.

We mixed tgrB1^AX4tgrC1^AX4–GFP cells with incompatible tgrB1^QS31tgrC1^QS31–RFP at 1:1,000 and allowed them to develop. Multicellular structures were photographed by fluorescent confocal microscopy at a fixed position over the indicated times. (a) Loose aggregates. (b) Tight aggregates. (c) Slugs. (d) Fruiting bodies. The white arrows indicate the position of the rare GFP cells. Scale bar, 200 μm.