Fig. 7. Characterisation of paxB knockout phenotypes. Comparison of Ax2 and an Ax2 paxB knockout strain (A,C) Ax2 and paxB^– in top view after 24 hours of development on agar. In Ax2 all cells develop to fruiting bodies, while in the paxB^– strains many cells do not develop into fruiting bodies but arrest at the mound stage, or when they continue development later development is grossly abnormal. (B,D) Ax2 and paxB^– knockout strain in side view after development on water agar for 24 hours. Note the differences in scale between images in B and D. Ax2 form fruiting bodies with slender stalks and well define basal disks while the paxB^– mutant often form small fruiting bodies on a large mass of cells that is not lifted off the substrate.