title: Osteonectin RNA and collagen alpha1(I) RNA in the developing rat maxilla.
abstract: The sequence of rat osteonectin mRNA was determined. Comparison with osteonectin (ON) mRNA sequences of other vertebrates showed a great similarity, but a stretch of codons deviated with respect to another rat strain, suggesting the possibility of two ON variants in rats. Northern blots exhibited one band of ON mRNA only. The expression of ON and collagen alpha1(I) RNA in tissues of the developing rat maxilla was studied by in situ hybridization. Both ON and collagen alpha1(I) RNA were observed concomitantly in osteoblasts, starting from the onset of bone formation at day 17 post coitum through the oldest age examined, day 20 after birth. A strict co-expression of the two sequences was also observed in odontoblasts as well as in fibroblasts of the periodontal ligament. In ameloblasts, neither ON nor collagen alpha1(I) RNA was detected under stringent hybridization conditions, but lower stringency led to an ON signal. Considering that ON is a secretory protein and the high stability of the ON mRNA, the co-expression of collagen alpha1(I) and ON RNA sequences in matrix-forming cells provided evidence that ON is a substantial component of collagen matrices.
authors.affiliation: Center for Oral Biology, Karolinska Institute, Huddinge, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Liao
authors.forename: C
authors.initials: C
authors.lastname: Brandsten
authors.forename: C
authors.initials: C
authors.lastname: Lundmark
authors.forename: C
authors.initials: C
authors.lastname: Christersson
authors.forename: T
authors.initials: T
authors.lastname: Wurtz
mesh_terms: D000565:Ameloblasts / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D003094:Collagen / Q000235:genetics*; D005109:Extracellular Matrix / Q000378:metabolism; D014644:Genetic Variation; D017403:In Situ Hybridization; D008437:Maxilla / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D015676:Osteonectin / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D015676:Osteonectin; D012333:RNA, Messenger; D003094:Collagen