BMPs mediate lateral inhibition at successive stages in feather tract development.
The spacing of feather buds in a tract is thought to arise from the interaction between an inducing signal from the dermis and an inhibitory signal generated in the nascent buds. Local BMP-2 expression in the ectoderm precedes the formation of the ectodermal placodes, which are the first morphological sign of bud differentiation. We have altered the activity of BMP-2 or BMP-4 in the ectoderm of the feather field by expressing them or their inhibitor noggin using retroviral vectors. These experiments demonstrate that BMP-2 is necessary and sufficient to mediate the lateral inhibition that positions buds in a tract. After buds are initiated, BMP-2 and BMP-4 continue to inhibit the adoption of bud fates and help to specify the size and shape of the bud. They may do so in part by their regulation of Fgf receptor expression in both the ectoderm and dermis. Additional insights into pattern formation in the feather bud can be inferred from the effects of altered BMP activity on bud morphogenesis.
Noramly
S
S
Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
Morgan
B A
BA
D000818:Animals; D030801:Animals, Genetically Modified; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000235:genetics / Q000502:physiology*; D002352:Carrier Proteins; D002642:Chick Embryo; D005241:Feathers / Q000196:embryology*; D005346:Fibroblast Growth Factors / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D005822:Genetic Vectors; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008954:Models, Biological; D010641:Phenotype; D011506:Proteins / Q000235:genetics / Q000502:physiology; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000502:physiology; D012190:Retroviridae / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D016212:Transforming Growth Factor beta; D000099176:Noggin Protein
D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D005346:Fibroblast Growth Factors; D011506:Proteins; D017468:Receptors, Fibroblast Growth Factor; D016212:Transforming Growth Factor beta; D000099176:Noggin Protein; C525718:BMP2 protein, human; C525809:BMP4 protein, human; C525719:Bmp2 protein, mouse; C525810:Bmp4 protein, mouse