Expression and regulation of ROR-1 during early avian limb development.
ROR-1 is a member of the ROR family of tyrosine kinase like orphan receptors and is highly conserved among various species. We have isolated the chick ROR-1 ( cROR-1) and show that cROR-1 expression is high and restricted to the proximal limb region until HH-stage 25. At later stages, expression spreads towards the distal limb region. In order to determine the signals that control cROR-1 expression, factors known to be involved in limb patterning (FGFs, BMPs, SHH, retinoic acid) were applied to the developing limb. Whereas neither FGFs, BMPs, nor SHH affected cROR-1 expression, upregulation could be achieved by ectopic application of retinoic acid to the distal limb region. As retinoic acid also upregulated retinoic acid receptor beta ( Rar-beta), we assume that cROR-1 upregulation is mediated by Rar-beta. We conclude that ROR-1 signaling is an independently regulated pathway, which is involved in late rather than early limb development.
Rodriguez-Niedenführ
Marc
M
Institute of Anatomy and Cell Biology II, University of Freiburg, Freiburg, Germany.
Pröls
Felicitas
F
Christ
Bodo
B
D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning / Q000187:drug effects / Q000502:physiology; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002642:Chick Embryo / Q000502:physiology*; D003001:Cloning, Molecular; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D006614:Hindlimb / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D057094:Nuclear Receptor Subfamily 1, Group F, Member 1; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D057050:Receptor Tyrosine Kinase-like Orphan Receptors; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D015534:Trans-Activators; D014212:Tretinoin / Q000494:pharmacology; D015854:Up-Regulation; D014921:Wings, Animal / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*
D019485:Bone Morphogenetic Proteins; D057094:Nuclear Receptor Subfamily 1, Group F, Member 1; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D015534:Trans-Activators; D014212:Tretinoin; D005346:Fibroblast Growth Factors; C078716:ROR1 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D057050:Receptor Tyrosine Kinase-like Orphan Receptors