O’Donovan, Kevin J.Ma, KaijieGuo, HengchangWang, ChenSun, FangHan, Seung BaekKim, HyukminWong, Jamie K.Charron, JeanZou, HongyanSon, Young-JinHe, ZhigangZhong, Jian2014-12-022014O’Donovan, K. J., K. Ma, H. Guo, C. Wang, F. Sun, S. B. Han, H. Kim, et al. 2014. “B-RAF kinase drives developmental axon growth and promotes axon regeneration in the injured mature CNS.” The Journal of Experimental Medicine 211 (5): 801-814. doi:10.1084/jem.20131780. http://dx.doi.org/10.1084/jem.20131780.0022-1007http://nrs.harvard.edu/urn-3:HUL.InstRepos:13454857Activation of intrinsic growth programs that promote developmental axon growth may also facilitate axon regeneration in injured adult neurons. Here, we demonstrate that conditional activation of B-RAF kinase alone in mouse embryonic neurons is sufficient to drive the growth of long-range peripheral sensory axon projections in vivo in the absence of upstream neurotrophin signaling. We further show that activated B-RAF signaling enables robust regenerative growth of sensory axons into the spinal cord after a dorsal root crush as well as substantial axon regrowth in the crush-lesioned optic nerve. Finally, the combination of B-RAF gain-of-function and PTEN loss-of-function promotes optic nerve axon extension beyond what would be predicted for a simple additive effect. We conclude that cell-intrinsic RAF signaling is a crucial pathway promoting developmental and regenerative axon growth in the peripheral and central nervous systems.en-USJournal Article2014-12-0210.1084/jem.20131780