Spore germination in Dictyostelium discoideum is a model system with which to study gene expression in a simple eukaryote. The germination process consists of four stages: activation, postactivation lag, spore swelling, and myxamoeba emergence. The application of uv light at any time during germination, up until a point in late spore swelling which has previously been defined as the “competence point”, completely inhibits emergence. The competence point occurs approximately 30 min prior to the emergence of myxamoebae. The normal incorporation of radiolabeled leucine and the stage-specific synthesis of the enzymes alkaline phosphatase, trehalase, and β-glucosidase stop within 20 minutes after spores are exposed to a uv fluence of 250 J/m 2. These data suggest mRNA half-lives of less than 20 minutes for the above three enzymes. In the case of spores which have been activated by heat shock, the largest increase in specific activity of all three enzymes occurs after the competence point has been achieved. That is, a uv treatment of swollen spores at or after the competence point will result in the emergence of myxamoebae which are deficient in the three enzymes. It is probable, therefore, that these enzymes do not have a critical role in the myxamoebae emergence process. Instead, these enzymes may represent part of a developmentally controlled enzyme pattern which is coordinately expressed during germination, but which functions in the emerged and growing vegetative myxamoebae. Although preformed enzymes of the dormant spore may aid in the emergence process, it is evident that they alone are not sufficient for the completion of emergence. The enzymes which are essential to the emergence process itself must be synthesized prior to the competence point (i.e., during early and middle spore swelling). While the majority of these essential germination enzymes may be transcriptionally controlled, the possibility is not excluded that some essential emergence enzymes may results from translation of mRNA stored in the dormant spore.