Planarian Fission Induction Protocol

Abstract Planarian asexual reproduction via transverse fission is a size-dependent animal behavior that offers a robust context to investigate mechanisms coordinating growth, patterning, and function. During fission, planarians mechanically break off a portion of posterior tissue which will go on to regenerate into a clonal progeny. By optimizing husbandry techniques of the planarian Schmidtea mediterranea, we developed a protocol that robustly induces fission behavior. This technique permits the investigation of the effects of different experimental perturbations on planarian fission. Using visual scoring, successful fissions can be scored daily by counting fission progeny. While this protocol only measures successful fissions, constant video recording permits the measurement of unsuccessful fission attempts as well. The protocol consists of the optimal husbandry of worms, transfer of animals to dishes, and scoring of animal fissions over a 2-week period.