Skip to main content
Article
Facial development and type III collagen RNA expression: concurrent repression in the osteopetrotic (Toothless,tl) rat and rescue after treatment with colony-stimulating factor-1
Open Access Articles
  • Sandy C. Marks, Jr., University of Massachusetts Medical School
  • Carin Lundmark
  • Tilmann Wurtz
  • Paul R. Odgren, University of Massachusetts Medical School
  • Carole A. MacKay, University of Massachusetts Medical School
  • April Mason-Savas, University of Massachusetts Medical School
  • Steven N. Popoff
UMMS Affiliation
Department of Cell Biology
Date
6-18-1999
Document Type
Article
Subjects
Animals; Collagen; *Gene Expression Regulation, Developmental; Macrophage Colony-Stimulating Factor; Maxillofacial Development; Osteopetrosis; RNA; Rats; Rats, Mutant Strains
Abstract

The toothless (osteopetrotic) mutation in the rat is characterized by retarded development of the anterior facial skeleton. Growth of the anterior face in rats occurs at the premaxillary-maxillary suture (PMMS). To identify potential mechanisms for stunted facial growth in this mutation we compared the temporospatial expression of collagen I (Col I) and collagen III (Col III) RNA around this suture in toothless (tl) rats and normal littermates by in situ hybridization of specific riboprobes in sagittal sections of the head. In normal rats, the suture is S shaped at birth and becomes highly convoluted by 10 days with cells in the center (fibroblasts and osteoblast progenitors) expressing Col III RNA and those at the periphery (osteoblasts) expressing no Col III RNA but high amounts of Col I RNA throughout the growth phase (the first 2 postnatal weeks). In the mutant PMMS, cells were reduced in number, less differentiated, and fewer osteoblasts were encountered. Expression of Col I RNA was at normal levels, but centrosutural cells expressed Col III RNA only after day 6 and then only weakly. A highly convoluted sutural shape was never achieved in mutants during the first 2 postnatal weeks. Treatment of tl rats with the cytokine CSF-1 improved facial growth and restored cellular diversity and Col III RNA expression in the PMMS to normal levels. Taken together, these data suggest that normal facial growth in rats is related to expression of Col III RNAby osteoblast precursors in the PMMS, that these cells are deficient in the tl mutation and are rescued following treatment with CSF-1.

Rights and Permissions
Citation: Dev Dyn. 1999 Jun;215(2):117-25. Link to article on publisher's site
Related Resources
Link to Article in PubMed
PubMed ID
10373016
Citation Information
Sandy C. Marks, Carin Lundmark, Tilmann Wurtz, Paul R. Odgren, et al.. "Facial development and type III collagen RNA expression: concurrent repression in the osteopetrotic (Toothless,tl) rat and rescue after treatment with colony-stimulating factor-1" Vol. 215 Iss. 2 (1999) ISSN: 1058-8388 (Print)
Available at: http://works.bepress.com/paul_odgren/5/