1 2 3 4 5 6 7 8 9 10

		REFERENCES Chiag, C.; Litengtung, Y.; Lee, E.; Young, K.; Corden, J.; Westphal, H.; Beachy, P. (1996). Cyclopia and defective axial patterning in mice lacking Sonic hedgehog gene function. Nature. 383, 407-413. Crossley, P.; Martinez, S.; Martin, G. (1996)Midbrain development induced by FGF8 in the chick embryo. Nature. 380, pp. 66-68. Iseki, S.; Wilkie, A.; Morriss-Kay, G. (1999)Fgfr1and Fgfr2have distinctdifferentiation- and proliferation-related roles in the developing mouse skull vault. Development. 126, pp. 5611-5620. Gilbert, S. (2000) Developmental Biology: Sixth Edition. Sinauer Associates, Massachusettes. Ohuchi, H. ; Nakagawa, T.; Yamamoto, A.; Araga, A.; Ohata, T.; Ishimaru, Y.;Yoshioka, H.; Kuwana, T.; Nohno, T.; Yamasaki, M.; Itoh, N.; Noji, S. (1997) The mesenchymal factor, FGF10, initiates and maintains the outgrowth of the chick limb bud through interaction with FGF8, an apical ectodermal factor. Development. 124, pp. 2235-2244. Min, H.; Danilenko, D.; Scully, S.; Bolon, B.; Ring, B.; Tarpley, J.; DeRose, M.;Simonet, W. (1998)Fgf-10is required for both limb and lung development and exhibits striking functional similarity to Drosophila branchless. Genes & Development. 12, 3156-3161. Mohammadi, M.; Mcmahon, G.; Sun, L.; Tang, C.; Hirth, P.; Yeh, B.; Hubbard, S.;Schlessinger, J. (1997) Structures of the Tyrosine Kinase Domain of Fibroblast Growth Factor Receptor in Complex with Inhibitors. Science. 276, pp. 955-960. Sanz-Ezquerro, J.J. and Cheryll Tickle. (2000)Autoregulation of Shhexpression and Shhinduction of cell death suggest a mechanism for modulating polarising activity during chick limb development. Development: 127, pp. 481- 4823. Shigetani, Y.; Nobusada, Y.; Kuratani, S. (2000)Ectodermally Derived FGF8 Defines the MaxillomandibularRegion in the Early Chick Embryo:Epithelial-Mesenchymal Interactions in the Specification of the Craniofacial Ectomesenchyme. Developmental Biology. 228, pp.73-85.