Presenter(s): Paula Berry
Faculty Mentor(s): Megan Moerdyk-Schauwecker & Patrick Phillips
Poster 15
Session: Sciences
Inducibly switching the reproductive mode of a model multi-cellular organism would be a powerful tool with many applications in genetic, reproductive and evolutionary studies. The nematode Caenorhabditis elegans is a functional hermaphrodite, with most individuals in wild- type strains being self-fertile, somatic females. However, non-disjunction events during meiosis cause occasional males to appear in a population, also allowing for sexual reproduction (outcrossing). Using CRISPR/Cas9, a degron tag was added to a key sex determination protein, XOL-1. XOL-1 could then be targeted for degradation by the proteasome by placing the C. elegans strain on plates containing auxin (Indole-3-acetic acid), a plant hormone. This caused all male embryos to become non-viable, and created an exclusively self-fertilizing population. Unlike xol-1 null mutants, which cannot be switched back to producing viable males, this effect was easily reversed by moving individuals to a non-auxin containing plate, restoring outcrossing. This method enables the maintenance of exclusively self-fertilizing lines with outcrossing potential with less labor than existing methods, using benign chemicals. Furthermore, the creation of this strain gives finer controls over experiments by allowing the same, genetically identical, populations to be self-fertile or outcrossing in a controlled manner.