D. Alfandari, H. Cousin, A. Gaultier, B. G. Hoffstrom, and D. W. Desimone, Integrin alpha5beta1 supports the migration of Xenopus cranial neural crest on fibronectin, Dev. Biol, vol.260, pp.449-464, 2003.

A. Aronheim, Y. C. Broder, A. Cohen, A. Fritsch, B. Belisle et al., Chp, a homologue of the GTPase Cdc42Hs, activates the JNK pathway and is implicated in reorganizing the actin cytoskeleton, Curr. Biol, vol.8, pp.1125-1128, 1998.

P. Aspenstrom, A. Fransson, and J. Saras, Rho GTPases have diverse effects on the organization of the actin filament system, Biochem. J, vol.377, pp.327-337, 2004.

A. C. Berzat, J. E. Buss, E. J. Chenette, C. A. Weinbaum, A. Shutes et al., Transforming activity of the Rho family GTPase, Wrch-1, a Wntregulated Cdc42 homolog, is dependent on a novel carboxyl-terminal palmitoylation motif, J. Biol. Chem, vol.280, pp.33055-33065, 2005.

E. R. Block, M. A. Tolino, and J. K. Klarlund, Pyk2 activation triggers epidermal growth factor receptor signaling and cell motility after wounding sheets of epithelial cells, J. Biol. Chem, vol.285, pp.13372-13379, 2010.

A. Boureux, E. Vignal, S. Faure, and P. Fort, Evolution of the Rho family of ras-like GTPases in eukaryotes, Mol. Biol. Evol, vol.24, pp.203-216, 2007.
URL : https://hal.archives-ouvertes.fr/hal-02267395

L. C. Bradley, A. Snape, S. Bhatt, and D. G. Wilkinson, The structure and expression of the Xenopus Krox-20 gene: conserved and divergent patterns of expression in rhombomeres and neural crest, Mech. Dev, vol.40, pp.73-84, 1993.

D. C. Brady, J. K. Alan, J. P. Madigan, A. S. Fanning, and A. D. Cox, The transforming Rho family GTPase Wrch-1 disrupts epithelial cell tight junctions and epithelial morphogenesis, Mol. Cell. Biol, vol.29, pp.1035-1049, 2009.

H. Brazier, G. Pawlak, V. Vives, and A. Blangy, The Rho GTPase Wrch1 regulates osteoclast precursor adhesion and migration, Int. J. Biochem. Cell Biol, vol.41, pp.1391-1401, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00363586

A. Borchers, H. H. Epperlein, and D. Wedlich, An assay system to study migratory behavior of cranial neural crest cells in Xenopus, Dev. Genes Evol, vol.210, pp.217-222, 2000.

F. Broders-bondon, A. Chesneau, F. Romero-oliva, A. Mazabraud, R. Mayor et al., Regulation of XSnail2 expression by Rho GTPases, Dev. Dyn, vol.236, pp.2555-2566, 2007.
URL : https://hal.archives-ouvertes.fr/hal-00284041

M. C. Brown, K. A. West, and C. E. Turner, Paxillin-dependent paxillin kinase linker and p21-activated kinase localization to focal adhesions involves a multistep activation pathway, Mol. Biol. Cell, vol.13, pp.1550-1565, 2002.

M. Cheung, M. C. Chaboissier, A. Mynett, E. Hirst, A. Schedl et al., The transcriptional control of trunk neural crest induction, survival, and delamination, Dev. Cell, vol.8, pp.179-192, 2005.

Y. Y. Chuang, A. Valster, S. J. Coniglio, J. M. Backer, and M. Symons, The atypical Rho family GTPase Wrch-1 regulates focal adhesion formation and cell migration, J. Cell Sci, vol.120, pp.1927-1934, 2007.

E. G. Coles, L. A. Taneyhill, and M. Bronner-fraser, A critical role for Cadherin6B in regulating avian neural crest emigration, Dev. Biol, vol.312, pp.533-544, 2007.

S. J. Coniglio, S. Zavarella, and M. H. Symons, Pak1 and Pak2 mediate tumor cell invasion through distinct signaling mechanisms, Mol. Cell. Biol, vol.28, pp.4162-4172, 2008.

F. De-amicis, M. Lanzino, A. Kisslinger, G. Cali, P. Chieffi et al., Loss of proline-rich tyrosine kinase 2 function induces spreading and motility of epithelial prostate cells, J. Cell. Physiol, vol.209, pp.74-80, 2006.

J. De-calisto, C. Araya, L. Marchant, C. F. Riaz, and R. Mayor, Essential role of noncanonical Wnt signalling in neural crest migration, Development, vol.132, pp.2587-2597, 2005.

S. W. Deacon, A. Beeser, J. A. Fukui, U. E. Rennefahrt, C. Myers et al., An isoform-selective, small-molecule inhibitor targets the autoregulatory mechanism of p21-activated kinase, Chem. Biol, vol.15, pp.322-331, 2008.

L. J. Essex, R. Mayor, and M. G. Sargent, Expression of Xenopus snail in mesoderm and prospective neural fold ectoderm, Dev. Dyn, vol.198, pp.108-122, 1993.

S. Faure, M. A. Lee, T. Keller, P. Ten-dijke, and M. Whitman, Endogenous patterns of TGFbeta superfamily signaling during early Xenopus development, Development, vol.127, pp.2917-2931, 2000.

S. Fuchs, D. Herzog, G. Sumara, S. Buchmann-moller, G. Civenni et al., Stagespecific control of neural crest stem cell proliferation by the small rho GTPases Cdc42 and Rac1, Cell Stem Cell, vol.4, pp.236-247, 2009.

Y. Gao, J. B. Dickerson, F. Guo, J. Zheng, and Y. Zheng, Rational design and characterization of a Rac GTPase-specific small molecule inhibitor, Proc. Natl Acad. Sci. USA, vol.101, pp.7618-7623, 2004.

C. Gauthier-rouviere, E. Vignal, M. Meriane, P. Roux, P. Montcourier et al., RhoG GTPase controls a pathway that independently activates Rac1 and Cdc42Hs, Mol. Biol. Cell, vol.9, pp.1379-1394, 1998.
URL : https://hal.archives-ouvertes.fr/hal-02195846

M. Groysman, I. Shoval, and C. Kalcheim, A negative modulatory role for rho and rho-associated kinase signaling in delamination of neural crest cells, Neural Dev, vol.3, p.27, 2008.

L. Guemar, P. De-santa-barbara, E. Vignal, B. Maurel, P. Fort et al., The small GTPase RhoV is an essential regulator of neural crest induction in Xenopus, Dev. Biol, vol.310, pp.113-128, 2007.
URL : https://hal.archives-ouvertes.fr/hal-02267391

V. Hamburger and H. L. Hamilton, A series of normal stages in the development of the chick embryo, Dev. Dyn, vol.195, pp.231-272, 1951.

N. D. Hopwood, A. Pluck, and J. B. Gurdon, A Xenopus mRNA related to Drosophila twist is expressed in response to induction in the mesoderm and the neural crest, Cell, vol.59, pp.893-903, 1989.

X. Huang and J. P. Saint-jeannet, Induction of the neural crest and the opportunities of life on the edge, Dev. Biol, vol.275, pp.1-11, 2004.

Y. S. Hwang, T. Luo, Y. Xu, and T. D. Sargent, Myosin-X is required for cranial neural crest cell migration in Xenopus laevis, Dev. Dyn, vol.238, pp.2522-2529, 2009.

A. B. Jaffe and A. Hall, Rho GTPases: biochemistry and biology, Annu. Rev. Cell Dev. Biol, vol.21, pp.247-269, 2005.

J. Kashef, A. Kohler, S. Kuriyama, D. Alfandari, R. Mayor et al., Cadherin-11 regulates protrusive activity in Xenopus cranial neural crest cells upstream of Trio and the small GTPases, Genes Dev, vol.23, pp.1393-1398, 2009.

S. Kellerer, S. Schreiner, C. C. Stolt, S. Scholz, M. R. Bosl et al., Replacement of the Sox10 transcription factor by Sox8 reveals incomplete functional equivalence, Development, vol.133, pp.2875-2886, 2006.

C. Labonne and M. Bronner-fraser, Neural crest induction in Xenopus: evidence for a two-signal model, Development, vol.125, pp.2403-2414, 1998.

N. M. Le-douarin and E. Dupin, Multipotentiality of the neural crest, Curr. Opin. Genet. Dev, vol.13, pp.529-536, 2003.

J. P. Liu and T. M. Jessell, A role for rhoB in the delamination of neural crest cells from the dorsal neural tube, Development, vol.125, pp.5055-5067, 1998.

R. Manabe, M. Kovalenko, D. J. Webb, and A. R. Horwitz, GIT1 functions in a motile, multi-molecular signaling complex that regulates protrusive activity and cell migration, J. Cell Sci, vol.115, pp.1497-1510, 2002.

H. K. Matthews, L. Marchant, C. Carmona-fontaine, S. Kuriyama, J. Larrain et al., Directional migration of neural crest cells in vivo is regulated by Syndecan-4/Rac1 and non-canonical Wnt signaling/RhoA, Development, vol.135, pp.1771-1780, 2008.

R. Mayor, R. Morgan, and M. G. Sargent, Induction of the prospective neural crest of Xenopus, Development, vol.121, pp.767-777, 1995.

N. Nagoshi, S. Shibata, M. Nakamura, Y. Matsuzaki, Y. Toyama et al., Neural crest-derived stem cells display a wide variety of characteristics, J. Cell. Biochem, vol.107, pp.1046-1052, 2009.

S. Nie, Y. Kee, and M. Bronner-fraser, Myosin-X is critical for migratory ability of Xenopus cranial neural crest cells, Dev. Biol, vol.335, pp.132-142, 2009.

P. D. Nieuwkoop and J. Faber, Normal Table of Xenopus laevis, 1967.

C. Notarnicola, L. Le-guen, P. Fort, and P. De-santa-barbara, Dynamic expression patterns of RhoV/Chp and RhoU/Wrch during chicken embryonic development, Dev. Dyn, vol.237, pp.1165-1171, 2008.
URL : https://hal.archives-ouvertes.fr/inserm-00285415

S. Ory, H. Brazier, and A. Blangy, Identification of a bipartite focal adhesion localization signal in RhoU/Wrch-1, a Rho family GTPase that regulates cell adhesion and migration, Biol. Cell, vol.99, pp.701-716, 2007.
URL : https://hal.archives-ouvertes.fr/hal-02323488

R. J. Petrie, A. D. Doyle, and K. M. Yamada, Random versus directionally persistent cell migration, Nat. Rev. Mol. Cell Biol, vol.10, pp.538-549, 2009.

J. Rangarajan, T. Luo, and T. D. Sargent, PCNS: a novel protocadherin required for cranial neural crest migration and somite morphogenesis in Xenopus, Dev. Biol, vol.295, pp.206-218, 2006.

, R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, 2004.

A. J. Ridley, M. A. Schwartz, K. Burridge, R. A. Firtel, M. H. Ginsberg et al., Cell migration: integrating signals from front to back, Science, vol.302, pp.1704-1709, 2003.

S. H. Robertson, C. K. Smith, A. L. Langhans, S. E. Mclinden, M. A. Oberhardt et al., Multiscale computational analysis of Xenopus laevis morphogenesis reveals key insights of systemslevel behavior, BMC Syst. Biol, vol.1, p.46, 2007.

P. A. Rupp and P. M. Kulesa, A role for RhoA in the two-phase migratory pattern of post-otic neural crest cells, Dev. Biol, vol.311, pp.159-171, 2007.

A. Ruusala and P. Aspenstrom, The atypical Rho GTPase Wrch1 collaborates with the nonreceptor tyrosine kinases Pyk2 and Src in regulating cytoskeletal dynamics, Mol. Cell. Biol, vol.28, pp.1802-1814, 2008.

B. Sadaghiani and C. H. Thiebaud, Neural crest development in the Xenopus laevis embryo, studied by interspecific transplantation and scanning electron microscopy, Dev. Biol, vol.124, pp.91-110, 1987.

J. Saras, P. Wollberg, and P. Aspenstrom, Wrch1 is a GTPase-deficient Cdc42-like protein with unusual binding characteristics and cellular effects, Exp. Cell Res, vol.299, pp.356-369, 2004.

T. Sauka-spengler and M. Bronner-fraser, Evolution of the neural crest viewed from a gene regulatory perspective, Genesis, vol.46, pp.673-682, 2008.

D. Schiavone, S. Dewilde, F. Vallania, J. Turkson, F. Di-cunto et al., The RhoU/ Wrch1 Rho GTPase gene is a common transcriptional target of both the gp130/ STAT3 and Wnt-1 pathways, Biochem. J, vol.421, pp.283-292, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00479149

K. Schlessinger, A. Hall, and N. Tolwinski, Wnt signaling pathways meet Rho GTPases, Genes Dev, vol.23, pp.265-277, 2009.

A. Shutes, A. C. Berzat, E. J. Chenette, A. D. Cox, and C. J. Der, Biochemical analyses of the Wrch atypical Rho family GTPases, Methods Enzymol, vol.406, pp.11-26, 2006.

R. F. Spokony, Y. Aoki, N. Saint-germain, E. Magner-fink, and J. P. Saint-jeannet, The transcription factor Sox9 is required for cranial neural crest development in Xenopus, Development, vol.129, pp.421-432, 2002.

M. Symons, Adhesion signaling: PAK meets Rac on solid ground, Curr. Biol, vol.10, pp.535-537, 2000.

W. Tao, D. Pennica, L. Xu, R. F. Kalejta, and A. J. Levine, Wrch-1, a novel member of the Rho gene family that is regulated by Wnt-1, Genes Dev, vol.15, pp.1796-1807, 2001.

J. P. Thiery, H. Acloque, R. Y. Huang, and M. A. Nieto, Epithelial-mesenchymal transitions in development and disease, Cell, vol.139, pp.871-890, 2009.

E. Vignal, M. De-toledo, F. Comunale, A. Ladopoulou, C. Gauthier-rouviere et al., Characterization of TCL, a new GTPase of the rho family related to TC10 andCcdc42, J. Biol. Chem, vol.275, pp.36457-36464, 2000.

E. Vignal, P. De-santa-barbara, L. Guemar, J. M. Donnay, P. Fort et al., Expression of RhoB in the developing Xenopus laevis embryo, Gene Expr. Patterns, vol.7, pp.282-288, 2007.
URL : https://hal.archives-ouvertes.fr/hal-02267389

M. Weisz-hubsman, N. Volinsky, E. Manser, D. Yablonski, and A. Aronheim, Autophosphorylation-dependent degradation of Pak1, triggered by the Rho-family GTPase, Chp. Biochem. J, vol.404, pp.487-497, 2007.

C. F. Wu, C. Delsert, S. Faure, E. E. Traverso, M. Kloc et al., Tumorhead distribution to cytoplasmic membrane of neural plate cells is positively regulated by Xenopus p21-activated kinase 1 (X-PAK1), Dev. Biol, vol.308, pp.169-186, 2007.

X. Wu, X. Tu, K. S. Joeng, M. J. Hilton, D. A. Williams et al., Rac1 activation controls nuclear localization of beta-catenin during canonical Wnt signaling, Cell, vol.133, pp.340-353, 2008.

Z. S. Zhao, E. Manser, T. H. Loo, and L. Lim, Coupling of PAK-interacting exchange factor PIX to GIT1 promotes focal complex disassembly, Mol. Cell. Biol, vol.20, pp.6354-6363, 2000.