Fig. 4. puf-8 regulates the fusion of the distal vulval cells. Vulval cell fusion was analyzed at the Pn.px stage using AJM-1::GFP as a cell junction marker for unfused cells. (A-C) Wild-type, (D-F) puf-8(zh17) single mutants and (G-J) fbf-1(ok91) fbf-2(q704) double mutants. In all panels, anterior is to the left and ventral is to the bottom. In the graphs, white represents fused Pn.px cells, grey indicates fusing Pn.px cells that have started to dissolve their junctions as can be seen for the P8.px cells in G, and black indicates unfused cells with intact AJM-1::GFP-positive junctions. Note that the fraction of unfused cells in fbf-1(ok91) fbf-2(q704) double mutants matches the frequency of ectopically induced distal cells that give rise to the 28% penetrant Muv phenotype (see Table 2, row 13). Scale bar in B: 10 µm.