DORSOVENTRAL AXIS SPECIFICATION

DORSOVENTRAL AXIS SPECIFICATION

11.5.      Dorsoventral Axis specification

The Dorsoventral signalling centre present in the dorsal ectoderm that is significant for patterning of ventral flexors muscles and dorsal extensors muscles. The critical morphogen considered for Dorsoventral polarity is the Wnt7a, expressed in ectodermal cells to induce the expression of Lmx1 gene in the underlying mesoderm that specifies the dorsal phenotype. The Wnt7a is both critical and sufficient to dorsalize the limb and its deficiency or inactivation may lead to a genetic defect named as Nail-patella syndrome.

The cellular origin during limb development in the form of Limb cartilage and bone cells are derived from LPM. It leads with the help of BMP morphogens BMP2 and BMP4. BMP2 and BMP4 are crucial to achieving chondrogenesis and later bone formation. Skeletal muscles of the limb are derived from somites (myotome) and dermal cells from the dermomyotome.


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