Protein kinase modulators interfere with bud formation in Hydra vulgaris

The fresh water polyp Hydra can reproduce asexually by forming buds. These buds separate from the parent animal due to the development of foot tissue in a belt-like region and the formation of a constriction basal to that region. A single pulse treatment with activators of protein kinase C, including 1,2-dioctanoyl-rac-glycerol and 12-O-tetradecanoylphorbol-13-acetate, and inhibitors of various protein kinases, including staurosporine, H-7 and genistein, interfered with foot and constriction formation. The buds did not separate. Therewith, branched animals were formed, some of which bore a lateral foot patch. Simultaneous treatments with an activator and inhibitor led to a higher amount of branched animals than treatments with one of these agents alone. Based on the different specificities of the activators and inhibitors used we propose that activation of a protein kinase C and/or inhibition of a probably non-C-type protein kinase interfere with the decrease of positional value at the bud's base, a process necessary to initiate the pattern forming system leading to foot formation.