Pattern formation and regulation of gene expressions in chick recombinant limbs.
Recombinant limbs were performed by ensembling dissociated-reaggregated wing bud mesoderm inside an ectodermal hull. The zone of polarizing activity was excluded from the mesoderm used to perform the recombinant limbs (non-polarized recombinants), and grafted when desired (polarized recombinants). Reorganization of patterning progressively occurred in the newly formed progress zone under the influence of the apical ectodermal ridge (AER), explaining the proximo-distal gradient of morphogenesis observed in developed recombinant limbs. The AER, without the influence of the polarizing region (ZPA), was sufficient to direct outgrowth and appropriate proximo-distal patterning, as observed in the expression of the Hoxa-11 and Hoxa-13 genes. The development of the recombinant limbs coursed with symmetric AER and downregulation of Bmp expression in the mesoderm supporting a negative effect of Bmp signaling upon the apical ridge. The recombinant ectoderm maintained previously established compartments of gene expressions and organized a correct dorso-ventral patterning in the recombinant progress zone. Finally, the ZPA effect was only detected on Bmp expression and pattern formation along the antero-posterior axis.
Elisa Piedra
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Departamento de Anatomía y Biología Celular, Facultad de Medicina, Universidad de Cantabria, 39011, Santander, Spain.
Borja Rivero1
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Fernandez-Teran
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Ros
M A
MA
D000818:Animals; D030161:Avian Proteins; D001368:Axis, Cervical Vertebra / Q000196:embryology; D019521:Body Patterning / Q000502:physiology*; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000235:genetics; D002642:Chick Embryo; D005121:Extremities / Q000196:embryology; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics; D009024:Morphogenesis; D011506:Proteins / Q000235:genetics; D011518:Proto-Oncogene Proteins; D011784:Quail; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins
D030161:Avian Proteins; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; C513076:EN1 protein, human; C484298:HOXA11 protein, human; D018398:Homeodomain Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D016212:Transforming Growth Factor beta; C490509:WNT7A protein, Gallus gallus; D051153:Wnt Proteins; C099959:homeobox protein HOXA13; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors