title: Effects of localized application of transforming growth factor beta 1 on developing chick limbs.
abstract: The effects of exogenous transforming growth factor beta (TGF-beta) on chick limb development in vivo were studied by implanting carriers of TGF-beta 1 into developing wing buds. Agarose beads were soaked in solutions containing TGF-beta 1 and implanted into wing buds at stages 18 to 27. Localized application of TGF-beta 1 to distal regions of the wing bud caused specific skeletal elements in the limb to be reduced or absent. The particular proximal-distal limb element affected depended on the stage at which the bead was implanted. Position of the bead in the anterior-posterior axis also influenced the pattern of affected structures. Experiments in which TGF-beta 1 beads were implanted and then removed at 24- and 48-hr intervals indicate that there are specific periods during which a skeletal element appears to be sensitive to the effects of exogenous TGF-beta 1. In a few cases, beads placed in proximal positions in later staged limbs resulted in formation of ectopic cartilage near the bead. These results suggest that exposure to exogenous TGF-beta 1 in vivo influences the development of skeletal elements in the chick limb in a stage- and position-dependent manner.
authors.affiliation: Developmental Biology Center, University of California Irvine 92717.
authors.forename: T F
authors.initials: TF
authors.lastname: Hayamizu
authors.forename: S K
authors.initials: SK
authors.lastname: Sessions
authors.forename: N
authors.initials: N
authors.lastname: Wanek
authors.forename: S V
authors.initials: SV
authors.lastname: Bryant
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000002:abnormalities; D002356:Cartilage / Q000187:drug effects / Q000196:embryology* / Q000648:ultrastructure; D002470:Cell Survival / Q000187:drug effects; D002642:Chick Embryo / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010012:Osteogenesis / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014921:Wings, Animal / Q000196:embryology
chemical_list: D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta