BIOL 3010 Lecture Notes - Growth Factor, Nodal, Fibroblast
29 Jan 2013
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Document Summary
Spemann grafting experiments - developmental fate influenced by signals from neighboring cells. Instructive induction: inducing signal instructs one path over another ex/ ectoderm --> epidermis (no signal) Permissive induction: responding tissue responds to signal non- specifically (any inductive signal will do) permissive induction. **instructive inductions occur earlier during development permissive induction later during development (options narrowed)** Xenopus: ectoderm --> epidermis (if cultured alone) ectoderm --> mesoderm (if cultured with vegetal tissue) fibroblast growth factor, transformation growth factor- : can induce mesoderm differentiation in absence of vegetal tissue. Vg-1 nodal primitive node white, steel most potent inducer is activin (member of tgf- family) (however, its expression has yet to be found at the right time) Nodal - non-autonomous function (can be rescued by wt in chimeric mice) expressed in the primitive node, though which ectodermal cells must pass en route to forming mesoderm also a member of the tgf- family.
