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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 4217

Harriett E. Smith-Somerville, Martha A. Verchot, and Phillip E. Ryals; Food Vacuoles during Heat-Shock-Induced Transformation from the Microstomal to the Macrostomal Cell Type of Tetrahymena vorax. J.Protozool. 33(2):261-266, 1986

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The heat-shock method for induction of the macrostomal form of Tetrahymena vorax involves the transfer of cells to reduced nutrient medium and the application of a series of elevated temperature shocks followed by washing the protozoa into inorganic medium. The component of the procedure that had the greatest effect on food vacuoles was the heat shock. At the end of the heat shocks, cells formed vacuoles a lower rate than non-heat-shocked cells, but the size of the vacuoles formed was larger and the protozoa contained an increased number of vacuoles and total vacuolar membrane. The rate was further reduced by washing cells into non-nutrient medium. In the absence of the heat shocks, the medium had little effect on the capacity of the cells to form vacuoles although after 7.5 hr in inorganic medium, the vacuoles formed were smaller and the protozoa possessed fewer vacuoles and therefore less vacuolar membrane. The amount of membrane required to form the cytopharyngeal pouch of the macrostomal cell type was equivalent to the surface area of food vacuoles present in cells prior to the onset of the heat shocks, but the number and surface area of vacuoles decline between the time of oral resorption and pouch development.