The relationship between cyclic adenosine 3',5'-monophosphate and morphology in exponential phase Candida albicans

The relationship between changes in cyclic AMP content and germ tube formation in exponential phase Candida albicans was investigated using two simple media containing glucose plus ammonium chloride, or N-acetyl-D-glucosamine (GlcNAc). The glucose medium did not promote germ tube formation unless the cells were starved before inoculation, whereas the GlcNAc medium promoted germ tube formation in both non-starved and starved cells. The cyclic AMP content of exponential phase cells, non-starved cells and starved cells was 0.21, 0.34 and 0.64 pmol mg-1 dry wt, respectively. In glucose medium, cyclic AMP content in both non-starved cells and starved cells increased for a period of 60 min after inoculation, but then decreased for a further 120 min. The cyclic AMP content of non-starved cells and starved cells was 0.16 and 0.29 pmol mg-1 dry wt, respectively, after 180 min. The maximum percentage of non-starved cells with germ tubes was around 20%. Starved cells with germ tubes were observed after 40 min and reached a maximum (around 90%) after 140 min. The number of germ tubes remained constant for the next 40 min. In GlcNAc medium, the cyclic AMP content of both non-starved cells and starved cells showed a tendency to increase for 180 min. The content of non-starved cells and starved cells was 2.02 and 1.75 pmol mg-1 dry wt, respectively, after 180 min. Germ tube formation in non-starved cells started after 70 min, reached around 80% after 150 min, and remained stable for the next 30 min.(ABSTRACT TRUNCATED AT 250 WORDS)