Abstract
The specific activity of α-mannosidase (EC 3.2.1.24) has been found to increase more than a thousandfold during development of the cellular slime mold, Dictyostelium discoideum. The enzyme accumulates in both spore and stalk cells. Studies with preferential inhibitors of macromolecular synthesis indicate that accumulation of α-mannosidase requires concomitant protein synthesis and prior ribonucleic acid synthesis. Control of the period of synthesis by the overall developmental program is demonstrated in two temporally deranged morphological mutants. α-Mannosidase is found in lysosomes of D. discoideum in association with other acid hydrolases which may be involved in metabolism of extracellular polysaccharide.