Genetic specificity of induction:

mesenchyme may instruct the epithelium as to what sets of genes to activate, the responding epithelium can comply with these instructions only so far as its genome permits.

TLS Online TPP Program

#Id: 7410

#Unit 5. Developmental Biology

Once wingless and engrailed expression patterns are established in adjacent cells, this pattern must be maintained to retain the parasegmental periodicity of the body plan.

TLS Online TPP Program

#Id: 7411

#Unit 5. Developmental Biology

TLS Online TPP Program

#Id: 7412

#Unit 5. Developmental Biology

The maintenance of patterns is regulated by reciprocal interaction between neighboring cells: cells secreting Hedgehog protein activate wingless expression in their neighbors, and the Wingless protein signal, which is received by the cells that secreted Hedgehog, serves to maintain hedgehog (hh) expression

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#Id: 7413

#Unit 5. Developmental Biology

Wingless protein also acts in an autocrine fashion, maintaining its own expression

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#Id: 7414

#Unit 5. Developmental Biology

The homologue of β-catenin in Drosophila is Armadillo.

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#Id: 7415

#Unit 5. Developmental Biology

The homologue of TGF-β in Drosophila is Dpp.