Unformatted text preview: Fig. 13.10 Limb bud ectoderm expresses FGF8
throughout its extension Gilbert 9e,
Fig. 13.10 FGFs are expressed in specialized ectoderm throughout
its proximal-distal outgrowth. FGFs act as a mitogen
(stimulating proliferation) of underlying mesenchyme. The anterior-posterior position of
the limb bud determines its identity Forelimb (in chicks, wing) bud cells
express Tbx5, a transcription factor.
Gilbert 9e, Fig. 13.7 Hindlimb bud cells express Tbx4, a
similar transcription factor. Tbx5 is expressed in wings, Tbx4 in legs
Wing Tbx4 Tbx5 Leg Limb buds have mixed identity in limbs
that express both Tbx4 & 5 Gilbert 9e,
Fig. 13.7 Forelimb (in chicks, wing) bud cells normally
express Tbx5; hindlimb bud cells express Tbx4....
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- Fall '12
- Developmental Biology, Humpback whale, limb development, Gilbert 9e