BIOL303 Chapter Notes -Apical Ectodermal Ridge, Lateral Plate Mesoderm, Limb Bud
19 Dec 2013
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Document Summary
The genes that are involved in the a-p positioning of the developing limb bud are hox genes along the axes: describe the expression patterns of fgf8 and fgf10 in the developing limb bud and during limb outgrowth. Outline the model for the signalling pathway by which these expression patterns are consolidated and maintained. Fgf10 is initially expressed throughout the lateral plate mesoderm. The expression pattern is then restricted to the sites of limb bud formation by wnts specific for the fore limb and hind limb area. This localized expression in the lateral plate mesoderm then regulates fgf8 and wnt3a in the ectoderm of limb buds. The apical ectodermal ridge runs along the distal margin of the limb bud. It functions as a major signaling center with 3 major roles: Maintaining plasticity of underlying mesenchyme so that proliferation will lead to proximal to distal limb growth. Maintaining expression of molecules that generate the a-p axis.
