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Trabecular Bone Microarchitecture Evaluation in an Osteoporosis Mouse Model
Published on: September 8, 2023
Quantitative trait locus on chromosome X affects bone loss after maturation in mice
Shuzo Okudaira1, Motoyuki Shimizu, Bungo Otsuki
1Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Sakyo, Kyoto 606-8507, Japan.
Journal of Bone and Mineral Metabolism
|April 1, 2010
Summary
A specific gene region on chromosome X (Chr X) significantly reduces bone loss in female mice after maturation. This finding highlights the sex-specific genetic regulation of bone density and loss.
Area of Science:
- Genetics
- Bone Biology
- Mammalian Genetics
Background:
- Genetic factors influence peak bone mass and post-maturation bone loss.
- The role of polymorphic genes on chromosome X (Chr X) in modulating bone loss remains largely uncharacterized.
- A previously identified quantitative trait locus (QTL) on Chr X, Pbd3, showed suggestive linkage to bone mass in male mice.
Purpose of the Study:
- To elucidate the specific effects of the Pbd3 QTL on the skeletal phenotype.
- To investigate the sex-specific genetic mechanisms influencing bone loss after maturation.
Main Methods:
- Generation of a congenic mouse strain (P2.P6-X) with a Chr X interval from SAMP6 mice on a SAMP2 background.
- Assessment of bone phenotype using microcomputed tomography (microCT) and dual-energy X-ray absorptiometry (DXA).
- Analysis of serum bone turnover markers and histomorphometric parameters.
Main Results:
- The P2.P6-X congenic strain exhibited reduced bone loss compared to the control SAMP2 strain, as evidenced by microCT and DXA.
- Serum bone turnover markers were significantly lower in P2.P6-X mice at 4 months but not at 8 months.
- These protective effects against bone loss were observed exclusively in female mice.
Conclusions:
- A QTL located within a 45.6-cM interval on Chr X is sex-specifically associated with the rate of bone loss post-maturation.
- This study identifies a novel genetic locus on Chr X that influences bone loss in a sex-dependent manner.
- The findings contribute to understanding the genetic basis of osteoporosis and potential therapeutic targets.
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