Lohann Excoffon

Genetic transformations are critical in genetic research and the treatment of some diseases. Transformations are when you express foreign DNA in a host organism. In order to educate students on transformations, kits can be created to give students hands-on experiences with this technique to learn genetics. However, currently available educational kits lack proper safety features for students. The yeast species Saccharomyces cerevisiae has the ability to take in simple circular DNA molecules (plasmids). These plasmids can be used to add specific genes to yeast cells.  Specially engineered plasmids—dubbed “art plasmids”—which were designed to genetically modify the color of a yeast sample are used in this work. The safety concern is that current art plasmids use Kanamycin—a hazardous chemical—as a selective marker, making it unsafe to use in an educational setting. Additionally, plasmids currently being used are missing a key pigment: green. By developing and running transformation procedures, we can address and solve these problems, and the educational kit will be one big step closer to being ready for distribution throughout schools. Here, I amplify a non-toxic selector gene, CaUra3MX. Then, as the yeast sample is transformed with each art plasmid, I swap the CaUra3MX gene with the toxic KanMX gene through homologous recombination, then plate the transformed cells on their respective medium. The transformed yeast cells were then stored in Glycerol to be used for the kit. To achieve a green pigmentation, I transform a blue art plasmid with a Histidine resistance gene (His3MX) and co-transform it with an orange art plasmid with the KanMX gene. The results of the co-transformation did not show green but the procedure will be edited and redone. Although not successful, the results of the co-transformation provide a good first step towards achieving a green-appearing color in yeast. Additionally, given the successful results of the KanMX swap, this procedure will be used for every remaining art plasmid in the kit to make them safe for high school use.

Research Paper