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Ontogenetic structural and material variations in ovine calcanei: a model for interpreting bone adaptation
John G Skedros1, Scott M Sorenson, Kenneth J Hunt
1Department of Orthopaedic Surgery, University of Utah, Salt Lake City, Utah, USA. jskedros@utahboneandjoint.com
Anatomical Record (Hoboken, N.J. : 2007)
|May 26, 2007
Summary
Sheep calcanei reveal distinct developmental timelines for structural bone traits. Genetic and epigenetic factors influence early trabecular development, while extragenetic factors shape later cortical and collagen adaptations.
Area of Science:
- Bone biology
- Developmental adaptations
- Mammalian skeletal morphology
Background:
- Investigating the interplay of genetic, epigenetic, and extragenetic factors in mammalian limb bone development is crucial.
- Sheep calcanei exhibit significant heterogeneity in structural and material organization by skeletal maturity, making them a suitable model.
Purpose of the Study:
- To examine regional and ontogenetic variations in sheep calcanei.
- To differentiate the influences of genetic, epigenetic, and extragenetic factors on bone development.
Main Methods:
- Analysis of cross-sections and radiographs from a fetal to adult sheep calcanei series.
- Evaluation of structural (cortical thickness, trabecular architecture) and material (ash content, collagen fiber orientation) characteristics.
Main Results:
- Cortical thickness and collagen fiber orientation showed delayed development, correlating with extragenetic factors like mechanical strain.
- Trabecular arch development in utero indicated strong genetic/epigenetic influences.
- Spatial and temporal variations in sheep calcanei provide a model for studying developmental mechanisms.
Conclusions:
- The study suggests expanding the traditional view of genetic and epigenetic factors to include extragenetic factors in bone development.
- Understanding these distinct influences is key to unraveling the mechanisms of developmental adaptations in limb bones.
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