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Variation in Bone Biomechanical Properties, Microstructure, and Density in BXH Recombinant Inbred Mice
Author(s) -
Turner Charles H.,
Hsieh YeouFang,
Müller Ralph,
Bouxsein Mary L.,
Rosen Clifford J.,
McCrann Margaret E.,
Donahue Leah Rae,
Beamer Wesley G.
Publication year - 2001
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1359/jbmr.2001.16.2.206
Subject(s) - quantitative computed tomography , bone mineral , anatomy , vertebra , bone density , cortical bone , femur , osteoporosis , lumbar vertebrae , biomechanics , biology , lumbar , endocrinology , paleontology
Abstract To test the hypothesis that factors associated with bone strength (i.e., volumetric bone mineral density [vBMD], geometry, and microstructure) have heritable components, we exploited the 12 BXH recombinant inbred (RI) strains of mice derived from C57BL/6J (B6; low bone mass) and C3H/HeJ (C3H; high bone mass) progenitor strains. The femurs and lumbar vertebrae from each BXH RI strain were characterized for phenotypes of vBMD, microstructural, biomechanical, and geometrical properties. Methods included bending (femur) and compression (vertebra) testing, peripheral quantitative computed tomography (pQCT), and microcomputed tomography (μCT). Segregation patterns of femoral and vertebral biomechanical properties among the BXH RI strains suggested polygenic regulation. Femoral biomechanical properties were strongly associated with femoral width in the anteroposterior (AP) direction and cortical thickness‐geometric properties with complex genetic regulation. Vertebral vBMD and biomechanical properties measured in BXH RI strains showed a greater variability than either B6 or C3H progenitors, suggesting both progenitor strains have independent subsets of genes that yield similar vBMD and strength. The μCT and pQCT data suggested that the distribution of vertebral mineral into cortical and trabecular compartments is regulated genetically. Although the B6 and C3H progenitors had similar vertebral strength, their vertebral structures were markedly different: B6 had good trabecular bone structure and modest cortical bone mineral content (BMC), whereas C3H had high cortical BMC combined with a deficiency in trabecular structure. These structural traits segregated independently in the BXH RI strains. Finally, vertebral strength was not correlated consistently with femoral strength among the BXH RI strains, suggesting genetic regulation of bone strength is site specific.