Synthesis of nucleic acids and proteins in the dimorphic forms ofCandida albicans

Abstract

Candida albicans grown in tissue culture medium 199 buds when incubated at 25°C. but produces filaments when incubated at 37°C. Macromolecular synthesis by budding and filament producing blastospores of C. albicans grown at these 2 temperatures of incubation was studied. Cells incubated at 25°C. reproduced by budding with a generation time of 2 hr. The dry weight, protein and DNA increased 2-fold as the cells doubled in number while the RNA content of such cells increased about 3·2-fold. Ninety-five per cent of cells incubated at 37°C. produced filaments in 3 hr. A net increase in protein of 49% and in RNA of 94% was detected within the first 2 hr. of incubation at 37°C. By 4 hr. incubation protein had increased to 220% of the initial value and RNA to 300%. DNA content did not increase during the first 2 hr. of incubation but by 3 hr. the DNA content had increased to 50% of the initial value. Electrophoretic analysis of the water soluble proteins from budding and filament producing cells revealed that both types of cells had 6 protein bands in common. Four bands were found in budding cells which did not appear in filament producing cells and a single protein band which did not occur in budding cells was observed in filament producing cells.