A model system for the study of gene expression in the undergraduate laboratory.

The flow of genetic information from DNA to RNA to protein, otherwise known as the "central dogma" of biology, is one of the most basic and overarching concepts in the biological sciences. Nevertheless, numerous studies have reported student misconceptions at the undergraduate level of this fundamental process of gene expression. This study reports on the efficacy of a model system for teaching gene expression in the undergraduate laboratory. A student-centered investigation of Tgfb1 gene expression in two murine melanoma cell lines was used to emphasize not only the process of gene expression but also various research methods for studying this phenomenon. Traditional RT-PCR, quantitative real-time RT-PCR, and flow cytometry-based in situ hybridization assays were employed to study expression of this immunosuppressive cytokine gene in the highly tumorigenic B16-F1 melanoma cell line and the poorly tumorigenic D5.1G4 melanoma cell line, both at the population and single-cell levels. A pre- and post-laboratory assessment instrument demonstrated the utility of this model system in enhancing student learning both of content related to gene expression and of research methods and data analysis skills. The pedagogical approach described in this study is therefore an effective way to improve the teaching and learning of gene expression at the undergraduate level.