Bringing immersive science to undergraduate laboratory courses using CRISPR gene knockouts in frogs and butterflies

The use of CRISPR/Cas9 for gene editing offers new opportunities for biology students to perform genuine research exploring the gene-to-phenotype relationship. It is important to introduce the next generation of scientists, health practitioners and other members of society to the technical and ethical aspects of gene editing. Here, we share our experience leading hands-on undergraduate laboratory classes, where students formulate hypotheses regarding the roles of candidate genes involved in development, perform loss-of-function experiments using programmable nucleases and analyze the phenotypic effects of mosaic mutant animals. This is enabled by the use of the amphibian Xenopus laevis and the butterfly Vanessa cardui, two organisms that reliably yield hundreds of large and freshly fertilized eggs in a scalable manner. Frogs and butterflies also present opportunities to teach key biological concepts about gene regulation and development. To complement these practical aspects, we describe learning activities aimed at equipping students with a broad understanding of genome editing techniques, their application in fundamental and translational research, and the bioethical challenges they raise. Overall, our work supports the introduction of CRISPR technology into undergraduate classrooms and, when coupled with classroom undergraduate research experiences, enables hypothesis-driven research by undergraduates.