Microstome-Macrostome Transformation in Tetrahymena vorax Strain V2 Type S Induced by a Transforming Principle, Stomatin

SYNOPSIS. Microstome →macrostome transformation in Tetrahymena vorax was induced by suspending microstomes in a transforming principle, stomatin, released by a potential prey, T. pyriformis. It was found that 70–90% of the microstomes formed macrostomes within 7 hours following suspension in this transforming principle. Macrostome formation occurred by the process of oral replacement. This process involved resorption of the microstome oral apparatus and its replacement with a larger (macrostome) one, which arose from an anarchic field that formed behind the resorbing oral area. Ninety-five percent of those microstomes which were destined to form macrostomes were in some stage of oral replacement 195 minutes after their suspension in stomatin. Several commercially produced products were tested over a wide range of concentrations to determine their ability to act as an inducer of macrostomes. Only 2, Trypticase and Bactocasitone, had any activity, and it was too small to be considered really effective. An attempt was also made to destroy the activity of stomatin by using enzymes. RNAse was effective but only in very high concentrations, so it was suggested that this activity might be related to the destruction of RNA within the transforming cell and not related to hydrolysis of stomatin. None of the other enzymes tested had any effect in reducing the activity of stomatin.