Differences in gene expression between the otic capsule and other bones

Hear Res. 2010 Jun 14;265(1-2):83-9. doi: 10.1016/j.heares.2010.02.006. Epub 2010 Feb 8.


Our long term goal is to understand the molecular pathology of otosclerosis and to develop better forms of therapy. Toward this goal, the current study focused on characterizing the molecular factors responsible for the unique biological features of the otic capsule: its minimal rate of remodeling, and lack of healing capacity when fractured. We compared expression levels of 62 genes involved in bone metabolism between the adult murine otic capsule and the tibia and parietal bones; the latter exemplify bones formed by endochondral and intramembranous ossification, respectively. Gene expression levels were measured using real-time quantitative RT-PCR and analyzed using tools of bioinformatics. Expression patterns of key genes were verified with in situ hybridization. The molecular profile of the otic capsule was distinctly different from that of the tibia and parietal bone. Genes found to be most characteristic of the otic capsule were: osteoprotegerin (opg), bone morphogenetic protein receptor 1b (bmpr1b) and bone morphogenetic protein 3 (bmp3). Expression levels were high for opg and bmpr1b, and minimal for bmp3 within the otic capsule. We concluded that opg and bmpr1b likely play important roles in inhibition of remodeling within the otic capsule.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bone Morphogenetic Protein 3 / genetics
  • Bone Morphogenetic Protein Receptors, Type I / genetics
  • Bone Remodeling / genetics*
  • Computational Biology
  • Ear, Inner / chemistry*
  • Gene Expression Profiling / methods
  • Gene Expression Regulation*
  • In Situ Hybridization
  • Mice
  • Mice, Inbred C57BL
  • Osteoprotegerin / genetics
  • Parietal Bone / chemistry*
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis*
  • Tibia / chemistry*


  • Bmp3 protein, mouse
  • Bone Morphogenetic Protein 3
  • Osteoprotegerin
  • RNA, Messenger
  • Tnfrsf11b protein, mouse
  • Bmpr1b protein, mouse
  • Bone Morphogenetic Protein Receptors, Type I