Studies of Macrostome Formation of Low-Transforming Tetrahymena vorax. Transformation Enhancers, Generation Time, and Membrane Fluidity

Low-transforming populations of Tetrahymena vorax are known to arise spontaneously in subculture and may retain the low-transforming characteristic for several years. In this paper, the authors present evidence that iron, copper, retinol palmitate (synthetic vitamin A), and elevated hydrogen ion concentration enhance heat-shock-induced macrostome formation and that the time required for maximum transformation is approximately that of the doubling time of the low-transforming population. The effect of transformation-enhancing compounds on cell division and membrane fluidity as inferred by polarization of fluorescence was also investigated.