Abstract
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 proα2(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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 172-176 |
| Number of pages | 5 |
| Journal | Calcified Tissue International |
| Volume | 62 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1998 |
Fingerprint
Keywords
- Bone
- Collagen
- Homotrimer
- Oim
- Osteogenesis imperfecta
ASJC Scopus subject areas
- Endocrinology
Cite this
Bone geometry and strength measurements in aging mice with the oim mutation. / McBride, D. J.; Shapiro, Jay; Dunn, M. G.
In: Calcified Tissue International, Vol. 62, No. 2, 1998, p. 172-176.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Bone geometry and strength measurements in aging mice with the oim mutation
AU - McBride, D. J.
AU - Shapiro, Jay
AU - Dunn, M. G.
PY - 1998
Y1 - 1998
N2 - 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 proα2(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.
AB - 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 proα2(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.
KW - Bone
KW - Collagen
KW - Homotrimer
KW - Oim
KW - Osteogenesis imperfecta
UR - http://www.scopus.com/inward/record.url?scp=2642692700&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=2642692700&partnerID=8YFLogxK
U2 - 10.1007/s002239900412
DO - 10.1007/s002239900412
M3 - Article
C2 - 9437052
AN - SCOPUS:2642692700
VL - 62
SP - 172
EP - 176
JO - Calcified Tissue International
JF - Calcified Tissue International
SN - 0171-967X
IS - 2
ER -