Control of Late Development of Dictyostelium discoideum by Proteins Functioning at Early Stages: (D. discoideum development/mutants/temperature-shift/two-dimensional gel).

We examined two mutants of D. discoideum which are temperature-sensitive for development. At the nonpermissive temperature one mutant becomes arrested in development during the transition from the finger to the migrating slug. Temperature-shift experiment indicates that the temperature-sensitive period begins at considerably earlier tip-forming stage. The other mutant becomes arrested at the Mexican hat stage and the temperature-sensitive period coinsided with this stage. The analysis of protein synthesis by two-dimensional gels, however, showed specific changes at the nonpermissive temperature at an earlier finger-forming stage. These results indicate the presence of a control of late development by proteins at early stages.