A stem cell-derived neuronal culture model for mouse species variation in neurite growth

Stem cell-derived neurons represent a powerful experimental system for the study of axon growth and regeneration, cutting cost and technical challenges. We developed an in vitro system using stem cell-derived motor neurons to investigate phenotypic differences in neurite growth between mouse subspecies. Previously, neurons in CAST/EiJ mice (Mus musculus castaneus) were reported to regrow CNS axons after injury to a greater degree than other strains. Here, we assayed neurite outgrowth from stem cell-neurons in a fully in vitro system, in the abscence of injury signals. In this system, CAST/EiJ neurons grew longer axons than those of C57BL/6J and 129S6/SvEv origin. Additionally, CASTx129 hybrid neurons exhibit comparable neurite growth to CAST/EiJ, indicating a dominant genetic effect.