A Caenorhabditis elegans lab module provides experiential learning for molecular genetics students

Caenorhabditis elegans is an established biological model that is used as a genetic tool due to its many advantages, such as short life cycle, small size, and availability of mutant strains. I describe here a 7-week C. elegans lab module that was designed for an upper-level molecular genetics course. Students measured gene expression by using fluorescence microscopy and RT-qPCR assays, and they evaluated how genes influence animal behavior and aging by using chemotaxis and survival assays. To observe how genotypes influence phenotypes, wild-type and mutant worms, including mutants expressing green fluorescent protein, were used. Most of the students reported that they "liked/loved" all lab activities on microscopy, behavioral assay, survival analysis, RNA extraction, cDNA synthesis, qPCR, and data analysis in a post-survey using a 5-point Likert scale. Students also "agreed/strongly agreed" that they understood several genetic concepts, including "genotype vs. phenotype," "mutation," and "model organisms," and how these concepts apply to these lab activities. Although students expressed that they faced some challenges in counting worms in a stereomicroscope and in interpretation of variable data, they valued the variety of techniques, as well as the consistency and sequencing of this lab module. Overall, students appreciated the hands-on skills acquired by using C. elegans to explore concepts of genetics and molecular biology.