Effects of Tocopheryl Acetate on FLP1 Expression, Growth Rate, and Feeding Behavior of Tetrahymena thermophila

Abstract

The purpose of this experiment was to determine if tocopheryl acetate affects expression of the FLP1 gene and feeding behavior in Tetrahymena thermophila. Prior experiments have shown changes in feeding behavior caused by other tocopherols in the closely related Tetrahymena vorax. Tocopheryl acetate has also been shown to affect the surface tension of plasma membranes and therefore could affect the expression of the FLP1 gene, which encodes a Flippase. It was hypothesized that tocopheryl acetate will decrease the feeding activity, cell growth, and FLP1 expression in T. thermophila. To test this hypothesis, T. thermophila cells were randomly assigned to either a control or test group. A non-lethal solution of tocopheryl acetate was added to the test group, and then both groups were cultured for 72 hours. Feeding activity was determined using an India ink-based assay to count the number of vacuoles per T. thermophila cell once per day. Cell counts were determined using a hemocytometer. After culturing for 72 hours, RNA was extracted from both Tetrahymena cultures. RT-qPCR was performed to quantify the expression of FLP1 in both the control and test group. It was predicted that the Tetrahymena cells would show a decrease in feeding activity, in cell growth, and in expression of FLP1 when exposed to tocopheryl acetate.