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#tissue interaction

2 public questions tagged with this topic.

Induction Morphogen -ll

Which of the following correctly explains regional specificity of induction?

Epithelial-mesenchymal recombination experiments revealed that regional identity resides predominantly in mesenchyme rather than epithelium. When salivary, mammary or cutaneous mesenchyme is combined with simple epithelium, resulting branching pattern, histology and cytodifferentiation follow mesenchymal origin, not epithelial source. Mesenchyme secretes instructive signals such as FGF10, BMPs and Wnts in region-specific combinations that activate unique transcription programs in competent epithelium. This instructive interaction explains why ureteric mesenchyme induces tubules while lung mesenchyme induces buds, overriding any autonomous tendency of responding tissue during organogenesis.

Ref: Gilbert, Developmental Biology, 12th ed., Chapter 12: Epithelial-Mesenchymal Interactions and Regional Specificity.

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Eye Lens Induction -ll

Which of the following defines the process of reciprocal induction?

Reciprocal induction describes sequentially interdependent signaling where two tissues mutually induce and refine each other. In eye development optic vesicle first secretes BMP4 and FGF inducing head surface ectoderm to form lens placode expressing Pax6, Sox2, L-Maf. Lens placode then secretes FGFs inducing optic vesicle to invaginate into optic cup and differentiate into neural retina and retinal pigment epithelium. Lens does not differentiate autonomously, Pax6 activation still requires BMP, FGF8 does not suppress L-Maf. This bidirectional dependency exemplifies classic reciprocal induction ensuring coordinated eye assembly and lens-retina alignment and function.

Ref: Gilbert, Developmental Biology, 12th ed., Chapter 12: Reciprocal induction definition – lens and optic cup interdependence.

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