Assessing the Influence of HOX11 Genes on Calcaneal Trabecular Bone Formation88th Annual Meeting of the American Association of Physical Anthropologists (2019)
The calcaneus and pisiform have substantial functional significance to human and non-human primate locomotion. While the pisiform and calcaneus are developmentally paralogous structures, these bones have undergone drastically different morphological changes during human evolution: the pisiform has lost its growth plate and experienced truncation since divergence from Australopithecus, while the calcaneus has ballooned and increased the proportion of trabecular to cortical bone compared to apes. Hox11 genes are known to influence wrist and ankle development and Hoxa11 and Hoxd11 are known to be expressed around both the pisiform and calcaneus. Mutations to Hoxa11 or Hoxd11 produce dosage dependent changes in pisiform morphology, including truncation and disorganization of the pisiform growth plate, while mice with both genes knocked out lack a calcaneus. We test the hypothesis that alterations to Hoxa11 and Hoxd11 genes impact the internal trabecular structure within the calcaneus in a dosage-dependent manner. MicroCT scans indicate that calcanei of mice with mutations to three of the four Hoxa11 and Hoxd11 alleles are shorter than wild type, however no discernable differences were found in trabecular bone volume, thickness, connectivity, or orientation across genotypes. We found trabecular bone volume in male mice to be higher than in female mice, possibly making genotype differences difficult to determine. These results suggest that Hox11 patterning may impact calcaneal ossification and overall size, but appears to have little impact on trabecular formation. Further work is needed to parse the roles that pattern formation and mechanical responses during growth have on trabecular bone morphology.
Publication DateMarch, 2019
Citation InformationKelsey M Kjosness, Timothy M Ryan and Philip Reno. "Assessing the Influence of HOX11 Genes on Calcaneal Trabecular Bone Formation" 88th Annual Meeting of the American Association of Physical Anthropologists (2019)
Available at: http://works.bepress.com/philip-reno/24/