Overexpression of the BMP antagonist Noggin in the interdigital mesenchyme of a developing mouse paw prevents the normal regression of soft tissue between the digits. The developmental process blocked by this experiment is:

• A Apoptosis mediated by BMP signalling ✓
• B Epithelial-mesenchymal transition of palatal shelves
• C Neuronal pruning by trophic factor withdrawal
• D Chondrogenic condensation of digital rays

Explanation

Separation of the digits depends on BMP-driven apoptosis of the interdigital mesenchyme. BMP signalling activates caspases in these cells, and blocking BMP with Noggin produces persistent webbing resembling syndactyly. Palatal shelf fusion involves EMT at the medial edge epithelium, neuronal pruning occurs after target contact in the periphery, and chondrogenic condensation forms the digital rays themselves rather than removing tissue between them.

Reference: Larsen's Human Embryology, 5th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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