Arginylation Regulates Neural Crest Migration 44. Anderson RB, Stewart AL, Young HM (2006) Phenotypes of neural-crest- derived cells in vagal and sacral pathways. Cell Tissue Res 323: 11–25. 45. Young HM, Newgreen D (2001) Enteric neural crest-derived cells: origin, identification, migration, and differentiation. Anat Rec 262: 1–15. 46. Perris R, Perissinotto D (2000) Role of the extracellular matrix during neural crest cell migration. Mech Dev 95: 3–21. 47. Chakraborty G, Ingoglia (1993) N-terminal arginylation and ubiquitin- mediated proteolysis in nerve regeneration. Brain Res Bull 30: 439–445. 48. Liu P, Jenkins NA, Copeland NG (2003) A highly efficient recombineering-based method for generating conditional knockout mutations. Genome Res 13: 476–484. 49. Matsuo I, Kuratani S, Kimura C, Takeda N, Aizawa S (1995) Mouse Otx2 functions in the formation and patterning of rostral head. Genes Dev 9: 2646–2658. 50. Wilkinson DG (1992) Whole mount in situ hybridization of vertebrate embryos. In: Wilkinson DG, ed. In Situ Hybridization, A Practical Approach. Oxford: IRL Press. pp 75–83. PLoS Genetics | www.plosgenetics.org 16 March 2010 | Volume 6 | Issue 3 | e1000878