SUMMARY: The morphogenetic capacity of E. coli was studied by converting the rod-shaped cells into spheres and then determining whether these spheres could revert to rods. The morphogenesis of cells was followed by immobilizing them in a viscous Methocel-containing medium. Two different types of spheres were prepared: cells which retained a mechanically intact sacculus, and osmotically sensitive sphaero-plasts lacking a sacculus. The sphaeroplasts were not able to revert to rods although they were able to synthesize a new sacculus. In contrast, spheres which had retained an intact sacculus were able to reshape themselves into rods. They were also able to form new ends at (or near) the sites of the ends on the original rods.
SUMMARY: Cytochalasin B inhibited the radial growth rate of Polyporus biennis, and caused an increase in hyphal density through a reduction in the distance between successive branches. Cytochalasin B also produced irregular hyphal profiles and, in a small percentage of hyphae, forked apices. The position of clamp connexions was little affected by cytochalasin B, but the developmental process was specifically inhibited during initiation and during the last two stages, when contact and dissolution of the clamp were occurring. There were no major disruptions of the ultrastructure of the dolipore/parenthesome septum caused by cytochalasin B treatment.