Use of a yeast (Saccharomyces cerevisiae) as a teaching marerial for high school genetics

Abstract

Yeasts are extensively used in molecular genetics as model eukaryotic organisms, and thus are sometimes called “eukaryotic E. coli”. Unfortunately only a small number of attempts have been made at adapting yeasts as a teaching material of genetics in high school. I report here the results of molecular genetic experiments using a yeast as a material, which may be utilized in practical education in high school. Major results are summarized as follows :

1. A wild-type strain of yeast having functional mitochondria (ρ⁺) was treated with ethidium bromide to isolate mutants that have functionally abberrant mitochondria (ρ^–). Optimal concentration of ethidium bromide was about 50 µg/ml per 10⁶ cells/ml.

2. The activity of succinate dehydrogenase was used as a markar of mitochondrial function. The two types of cells were found to be clearly different in the enzymatic activity in the logarithmic growth phase.

3. These experiments were introduced into the class as student experiments. All of the experiments planned were successful. The reports of students and the results of preexperiment test and post-experiment test indicated that the students understood clearly the meaning of the experiments. Most of the students (total number was 43) expressed positive impressions to this practice of experiments.