RT Journal Article SR Electronic T1 N- and C-Terminal Domains of β-Catenin, Respectively, Are Required to Initiate and Shape Axon Arbors of Retinal Ganglion Cells In Vivo JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 6567 OP 6575 DO 10.1523/JNEUROSCI.23-16-06567.2003 VO 23 IS 16 A1 Tamira M. Elul A1 Nikole E. Kimes A1 Minoree Kohwi A1 Louis F. Reichardt YR 2003 UL http://www.jneurosci.org/content/23/16/6567.abstract AB We used deletion mutants to study β-catenin function in axon arborization of retinal ganglion cells (RGCs) in live Xenopus laevis tadpoles. A deletion mutant βcatΔARM consists of the N- and C-terminal domains of wild-type β-catenin that contain, respectively, α-catenin and postsynaptic density-95 (PSD-95)/discs large (Dlg)/zona occludens-1 (ZO-1) (PDZ) binding sites but lacks the central armadillo repeat region that binds cadherins and other proteins. Expression of ΔARM in RGCs of live tadpoles perturbed axon arborization in two distinct ways: some RGC axons did not form arbors, whereas the remaining RGC axons formed arbors with abnormally long and tangled branches. Expression of the N- and C-terminal domains of β-catenin separately in RGCs resulted in segregation of these two phenotypes. The axons of RGCs overexpressing the N-terminal domain of β-catenin developed no or very few branches, whereas axons of RGCs overexpressing the C-terminal domain of β-catenin formed arbors with long, tangled branches. Additional analysis revealed that the axons of RGCs that did not form arbors after overexpression of ΔARM or the N-terminal domain of β-catenin were frequently mistargeted within the tectum. These results suggest that interactions of the N-terminal domain of β-catenin with α-catenin and of the C-terminal domain with PDZ domain-containing proteins are required, respectively, to initiate and shape axon arbors of RGCs in vivo.