Transient downregulation of Bmp signalling induces extra limbs in vertebrates.
Bone morphogenetic protein (Bmp) signalling has been implicated in setting up dorsoventral patterning of the vertebrate limb and in its outgrowth. Here, we present evidence that Bmp signalling or, more precisely, its inhibition also plays a role in limb and fin bud initiation. Temporary inhibition of Bmp signalling either by overexpression of noggin or using a synthetic Bmp inhibitor is sufficient to induce extra limbs in the Xenopus tadpole or exogenous fins in the Danio rerio embryo, respectively. We further show that Bmp signalling acts in parallel with retinoic acid signalling, possibly by inhibiting the known limb-inducing gene wnt2ba.
Center of Regenerative Medicine in Barcelona, Barcelona 08003,  Spain.
Bea
B
Christen
Alexandre Miguel Cavaco
AM
Rodrigues
Monserrat Barragán
MB
Monasterio
Carme Fabregat
CF
Roig
Juan Carlos
JC
Izpisua Belmonte
D000818:Animals; D015153:Blotting, Western; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002352:Carrier Proteins; D005121:Extremities / Q000254:growth & development; D017403:In Situ Hybridization; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D012038:Regeneration / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D014982:Xenopus laevis / Q000254:growth & development* / Q000378:metabolism; D015027:Zebrafish / Q000254:growth & development* / Q000378:metabolism; D000099176:Noggin Protein
D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D011720:Pyrazoles; D011743:Pyrimidines; D000099176:Noggin Protein; C554430:LDN 193189