title: Separation and specificity of action of four morphogens from hydra.
abstract: A procedure is presented by which four previously described morphogenetic substances can be purified from hydra: an activator and an inhibitor of head formation and an activator and an inhibitor of foot formation. We show that all four substances act specifically. At low concentrations, the head factors only influence head and not foot formation, and the foot factors only influence foot and not head formation.
authors.affiliation: European Molecular Biology Laboratory, P.O. Box 102209, D-6900, Heidelberg, Germany.
authors.forename: H Chica
authors.initials: HC
authors.lastname: Schaller
authors.affiliation: European Molecular Biology Laboratory, P.O. Box 102209, D-6900, Heidelberg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schmidt
authors.affiliation: European Molecular Biology Laboratory, P.O. Box 102209, D-6900, Heidelberg, Germany.
authors.forename: Cok J P
authors.initials: CJ
authors.lastname: Grimmelikhuijzen
keywords: Budding; Hydra; Morphogenetic substances; Regeneration