The Effect of Basic Conditions on CDK1 Expression in Tetrahymena thermophila

Abstract

The goal of this project was to discover whether expression of the CDK1 gene in Tetrahymena thermophila, as well as their growth, are aected by changing the pH of the growth media. We hypothesized that expression of the CDK1 gene would decrease significantly when grown in basic media. The CDK1 gene encodes the protein Cyclin-Dependent Kinase, which functions to advance cells through various stages of the cell cycle. To test our hypothesis, Tetrahymena cultures were randomly assigned to either the control group, which was grown in media with a neutral pH, or a treatment group, which was grown in media with a basic pH of 8.5. Previous experiments showed that Tetrahymena were able to survive in pH levels up to 9.0, although their optimal survival was at a neutral pH. The control and experimental cultures were maintained for one week before being processed. Following the weeklong incubation, RNA extraction, reverse transcription, and PCR were conducted on the control and experimental groups to measure expression of CDK1. In order to look at growth rate, we used a hemocytometer to perform cell counts throughout the weeklong incubation. Because CDKs are a major component of the cell cycle, we predicted that expression of the CDK1 gene would decrease, and that growth rate would also decrease, in Tetrahymena cells cultured in a basic environment.