ANC-1 Promotes Axon Guidance in Touch Receptor and Motor Neurons in C. elegans

Axon guidance is the process by which axons in the developing nervous system grow to reach their synaptic targets. This process is mediated by intracellular proteins that direct migration of the axonal growth cone in response to attractive and repulsive cues. Anc-1 (abnormal nuclear anchorage) is a Caenorhabditis elegans gene which functions in anchoring the nucleus to the cytoskeleton, but has also been implicated in the neuronal development, including synapse formation and axon termination. Mutations in the anc-1 human ortholog, SYNE1 (Spectrin repeat containing, nuclear envelope 1), are known to cause spinocerebellar ataxia and are additionally associated with developmental disorders such as autism and schizophrenia. However, the role of SYNE1 in regulating axon development is not well understood. Here, we show that ANC-1 can promote axon guidance in multiple neuron types. We used two C. elegans fluorescent marker strains to score axon guidance defects in light touch receptor neurons (PLM, PVM, ALM, AVM) and motor neurons (DA, DB, VA, VB) in individuals carrying an anc-1 null allele, e1873. We found that anc-1(e1873) mutants display axon guidance defects in DA/DB motor neurons and posterior processes from the ALM cell body; we also saw increased overextension of the PLM axon, consistent with previous findings