title: Tissue-specific expression of GTPas RalA and RalB during embryogenesis and regulation by epithelial-mesenchymal interaction.
abstract: RalA and RalB are members of the Ras-like GTP-binding protein family. To investigate if Ral GTPases play a role in development, temporal and spatial patterns of RalA and RalB gene expression were examined during embryogenesis. RalA and RalB had tissue-specific pattern of expression in developing organs. Both GTPases were expressed in endodermal derivatives in the digestive tract, kidney, mesonephros, gonad, adrenal gland, trachea, and blood vessels. RalA and RalB were also expressed in the ectodermal derivatives in the brain, spinal cord, ganglia, eye, skin, hair, whiskers, and teeth. RalA and RalB were also expressed in some mesodermal tissues including the lung mesenchyme and myocardium. Tissue recombination experiments showed that of Ral expression was increased by epithelial-mesenchymal interaction in the lung, indicating that Ral expression is functionally regulated. These data identify that RalA and RalB as inducible GTPases in the developing embryo.
authors.affiliation: Yale Child Health Research Center, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA. zhiyong.zhao@yale.edu
authors.forename: Z
authors.initials: Z
authors.lastname: Zhao
authors.forename: S A
authors.initials: SA
authors.lastname: Rivkees
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004848:Epithelium; D020558:GTP Phosphohydrolases / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D006321:Heart / Q000196:embryology; D008168:Lung / Q000196:embryology / Q000378:metabolism; D008648:Mesoderm; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012867:Skin / Q000196:embryology / Q000378:metabolism; D014018:Tissue Distribution; D029867:Xenopus Proteins; D020725:ral GTP-Binding Proteins / Q000235:genetics*
chemical_list: C119391:RalB protein, Xenopus; D029867:Xenopus Proteins; D020558:GTP Phosphohydrolases; C118120:Rala protein, mouse; D020725:ral GTP-Binding Proteins