title: Developmental expression of 2ar (osteopontin) and SPARC (osteonectin) RNA as revealed by in situ hybridization.
abstract: 2ar has been identified as a gene inducible by tumor promoters and growth factors in a variety of cultured mouse cell lines (Smith, J. H., and D. T. Denhardt. 1987. J. Cell. Biochem. 34:13-22). Sequence analysis shows that it codes for mouse osteopontin, an RGDS-containing, phosphorylated, sialic acid-rich Ca++-binding protein originally isolated from bone (Oldberg, A., A. Franzen, and D. Heinegard. 1986. Proc. Natl. Acad. Sci. USA. 83:8819-8823; Prince, C. W., T. Oosawa, W. T. Butler, M. Tomana, A. S. Brown, and R. E. Schrohenloer. 1987. J. Biol. Chem. 262:2900-3907.). In this paper we use Northern blot analysis and in situ hybridization to localize expression of 2ar during mouse embryogenesis. 2ar RNA is first detected in developing limb bones and calvaria at 14.5 d p.c., in a population of cells distinct from those expressing SPARC (osteonectin). High levels of 2ar expression are also seen in the bone marrow-derived granulated metrial gland cells of the deciduum and placenta, and in a number of epithelial tissues, including embryonic and postnatal kidney tubules, uterine epithelium and sensory epithelium of the embryonic ear. The temporal and spatial pattern of 2ar expression seen in vivo suggests that the protein plays a wider role than previously realized, in processes which are not confined to bone development.
authors.affiliation: Laboratory of Molecular Embryology, National Institute for Medical Research, Mill Hill, London, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Nomura
authors.forename: A J
authors.initials: AJ
authors.lastname: Wills
authors.forename: D R
authors.initials: DR
authors.lastname: Edwards
authors.forename: J K
authors.initials: JK
authors.lastname: Heath
authors.forename: B L
authors.initials: BL
authors.lastname: Hogan
mesh_terms: D000818:Animals; D001846:Bone Development; D001842:Bone and Bones / Q000196:embryology; D002352:Carrier Proteins / Q000235:genetics*; D002448:Cell Adhesion; D002478:Cells, Cultured; D003656:Decidua / Q000502:physiology; D003907:Dexamethasone / Q000494:pharmacology; D004423:Ear / Q000196:embryology; D005260:Female; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D007668:Kidney / Q000196:embryology / Q000254:growth & development; D051379:Mice / Q000196:embryology*; D009693:Nucleic Acid Hybridization; D015676:Osteonectin; D053495:Osteopontin; D011374:Progesterone / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D012795:Sialoglycoproteins / Q000235:genetics* / Q000502:physiology; D014018:Tissue Distribution
chemical_list: D002352:Carrier Proteins; D015676:Osteonectin; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D053495:Osteopontin; D011374:Progesterone; D005346:Fibroblast Growth Factors; D003907:Dexamethasone