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cAMP and spore differentiation in Dictyostelium discoideum.
Author(s) -
Robert R. Kay
Publication year - 1982
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.79.10.3228
Subject(s) - dictyostelium discoideum , stalk , slime mold , inducer , spore , mycetozoa , biology , sporogenesis , dictyostelium , mutant , microbiology and biotechnology , cellular differentiation , extracellular , cell , biochemistry , gene , horticulture
The individual amoebae composing of Dictyostelium aggregate can differentiate into either stalk or spore cells according, it is believed, to the extracellular signals they receive. By inducing the differentiation of isolated cells we hope to identify these signals. It is shown here that wild-type cells can differentiate into prespore cells in a solution of cAMP plus salts supplemented by conditioned medium. Cell-to-cell contact is not required. More important, isolated cells of various sporogenous mutant strains form spores in similar conditions without needing conditioned medium at all. For these strains at least, cAMP is the sole inducer necessary for spore formation. Earlier work has shown that stalk cells are induced by a combination of cAMP and a low molecular weight factor, differentiation inducing factor (DIF). DIF now appears to be the only pathway-specific inducer involved in the differentiation of sporogenous amoebae and DIF levels in the aggregate may therefore determine whether an amoeba becomes a stalk or a spore cell. In suitable conditions some sporogenous mutants form migrating slugs having an anterior/posterior pattern of prestalk and prespore cells. This pattern could be generated by the localized activity of DIF.