| First Author | McBride DJ Jr | Year | 1998 |
| Journal | Calcif Tissue Int | Volume | 62 |
| Issue | 2 | Pages | 172-6 |
| PubMed ID | 9437052 | Mgi Jnum | J:45596 |
| Mgi Id | MGI:1195751 | Doi | 10.1007/s002239900412 |
| Citation | McBride DJ Jr, et al. (1998) Bone geometry and strength measurements in aging mice with the oim mutation. Calcif Tissue Int 62(2):172-6 |
| abstractText | Mice with the naturally occurring oim mutation allows investigation of bone pathobiology in the setting of one mutation: a G deletion in the murine Cola-2 gene (exon 52) encoding the pro alpha 2(I) C-propeptide. As a result, normal sized mRNA is transcribed, but no secreted protein has been identified in oim/oim fibroblasts or osteoblasts, Here we report longitudinal changes in body mass, bone geometry, and bone structural properties of femurs tested in torsion from wild type (+/+) mice and mice homozygous (oim/oim) and heterozygous (+/oim) for the oim mutation. Femurs from mice 3 months, 6 months, 12 months, and > 18 months of age were dissected and X-ray films were taken in anterioposterior and mediolateral views to estimate the geometric properties. The metaphyseal ends of femurs were potted in polymethylemethacrylate and mounted on a torsional test fixture designed to convert axial tensile deformation to a torsional load using an INSTRON model 4204 materials tester. Compared with +/+ samples, peak torque at failure was reduced in oim/oim mice. Also, the geometric distribution of midshaft bone for oim/oim mice in terms of cortical area and polar moment was significantly reduced. However, the impact of the mutation on bone distribution was relatively minor for +/oim mice. Consistent with a type III classification in human OI patients, the presence of two nonfunctional alleles in homozygous oim mice significantly reduced body mass compared with age-matched wild type mice. However, no statistical difference in body mass was detected between +/ oim and +/+ mice. The absence of a gross phenotypic difference between +/oim and +/+ mice demonstrates a milder phenotype in +/oim mice. |
