title: Axonal regeneration and neuronal function are preserved in motor neurons lacking ß-actin in vivo.
abstract: The proper localization of ß-actin mRNA and protein is essential for growth cone guidance and axon elongation in cultured neurons. In addition, decreased levels of ß-actin mRNA and protein have been identified in the growth cones of motor neurons cultured from a mouse model of Spinal Muscular Atrophy (SMA), suggesting that ß-actin loss-of-function at growth cones or pre-synaptic nerve terminals could contribute to the pathogenesis of this disease. However, the role of ß-actin in motor neurons in vivo and its potential relevance to disease has yet to be examined. We therefore generated motor neuron specific ß-actin knock-out mice (Actb-MNsKO) to investigate the function of ß-actin in motor neurons in vivo. Surprisingly, ß-actin was not required for motor neuron viability or neuromuscular junction maintenance. Skeletal muscle from Actb-MNsKO mice showed no histological indication of denervation and did not significantly differ from controls in several measurements of physiologic function. Finally, motor axon regeneration was unimpaired in Actb-MNsKO mice, suggesting that ß-actin is not required for motor neuron function or regeneration in vivo.
authors: Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors: Thomas R
authors: TR
authors: Cheever
authors: Emily A
authors: EA
authors: Olson
authors: James M
authors: JM
authors: Ervasti
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D001369:Axons; D051379:Mice; D008822:Mice, Transgenic; D009046:Motor Neurons / Q000378:metabolism / Q000502:physiology*
chemical_list: D000199:Actins