Mouse genetic model for bone strength and size phenotypes: NZB/B1NJ and RF/J inbred strains.
Document Type
Article
Publication Date
2002
First Page
670
Last Page
674
JAX Source
Bone 2002 Dec; 31(6):670-4.
Abstract
The relationships of bone size, bone strength, and bone formation were investigated in two strains of mice, NZB/B1NJ and RF/J. Measurement of the femur midshaft size by peripheral quantitative computed tomography (pQCT) showed that the RF/J mice had a 32% greater cross-sectional area than NZB/B1NJ mice at 10 weeks of age, and a 38% greater cross-sectional area at 22 weeks of age. Body weight in the RF/J mice was 10% higher at 10 weeks but 9% lower at 22 weeks. Bone strength was determined by a three-point bending method. In agreement with the difference in bone cross-sectional area, the femurs of the RF/J mice were stronger (80% greater) and stiffer (80% greater) than the bones of the NZB/B1NJ mice. To determine whether periosteal bone formation played a role in the greater size of the RF/J mice, the mice were injected with tetracycline to label areas of new bone formation. Histomorphometrical analysis of the femur diaphysis demonstrated higher rates of periosteal bone formation (131% greater) and of periosteal forming surface (81% greater) in RF/J than in NZB/B1NJ mice. We conclude that a high rate of periosteal bone formation increases bone size and strength in RF/J mice when compared with NZB/B1NJ mice. The NZB/B1NJ and RF/J mice should be an excellent model to investigate the genes that regulate femur size and strength.
Recommended Citation
Wergedal JE,
Sheng MH,
Ackert BC,
Beamer WG,
Baylink DJ.
Mouse genetic model for bone strength and size phenotypes: NZB/B1NJ and RF/J inbred strains. Bone 2002 Dec; 31(6):670-4.