The effect of proteases on plasmodium formation in Didymium iridis.
An improved assay for quantitatively measuring the number of plasmodia formed with time is presented. Using this assay we have investigated the effects of three proteases, subtilisin PBN', subtilisin carlsberg and alpha-chymotrypsin. We have shown that 1) plasmodium formation is sensitive to protease treatment only during the first 2 h after mixing amoebae of compatible mating type but not after, 2) amoebae are protease sensitive when treated 1 h prior to mixing, 3) the two clones used have different sensitivities to protease treatment and 4) these effects are due to enzymatic activity and have little effect on viability. The meaning of these results in relation to recent evidence for a diffusible inducer of plasmodium formation is discussed.
D002459:Cell Fusion / Q000187:drug effects; D008858:Microscopy, Phase-Contrast; D009235:Myxomycetes / Q000187:drug effects / Q000502:physiology*; D010447:Peptide Hydrolases / Q000494:pharmacology*
D010447:Peptide Hydrolases