Congenic mice provide in vivo evidence for a genetic locus that modulates intrinsic transforming growth factor β1-mediated signaling and bone acquisition

Aditi Mukherjee, Emily A. Larson, Amy S. Carlos, John K. Belknap, Peter Rotwein, Robert F. Klein

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Osteoporosis, the most common skeletal disorder, is characterized by low bone mineral density (BMD) and an increased risk of fragility fractures. BMD is the best clinical predictor of future osteoporotic fracture risk, but is a complex trait controlled by multiple environmental and genetic determinants with individually modest effects. Quantitative trait locus (QTL) mapping is a powerful method for identifying chromosomal regions encompassing genes involved in shaping complex phenotypes, such as BMD. Here we have applied QTL analysis to male and female genetically-heterogeneous F2 mice derived from a cross between C57BL/6 and DBA/2 strains, and have identified 11 loci contributing to femoral BMD. Further analysis of a QTL on mouse chromosome 7 following the generation of reciprocal congenic strains has allowed us to determine that the high BMD trait, which tracks with the DBA/2 chromosome and exerts equivalent effects on male and female mice, is manifested by enhanced osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro and by increased growth of metatarsal bones in short-term primary culture. An insertion/deletion DNA polymorphism in Ltbp4 exon 12 that causes the in-frame removal of 12 codons in the DBA/2-derived gene maps within 0.6 Mb of the marker most tightly linked to the QTL. LTBP4, one of four paralogous mouse proteins that modify the bioavailability of the transforming growth factor β (TGF-β) family of growth factors, is expressed in differentiating MSC-derived osteoblasts and in long bones, and reduced responsiveness to TGF-β1 is observed in MSCs of mice homozygous for the DBA/2 chromosome 7. Taken together, our results identify a potential genetic and biochemical relationship between decreased TGF-β1-mediated signaling and enhanced femoral BMD that may be regulated by a variant LTBP4 molecule.

Original languageEnglish (US)
Pages (from-to)1345-1356
Number of pages12
JournalJournal of Bone and Mineral Research
Issue number6
StatePublished - Jun 2012
Externally publishedYes



ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Orthopedics and Sports Medicine


Dive into the research topics of 'Congenic mice provide in vivo evidence for a genetic locus that modulates intrinsic transforming growth factor β1-mediated signaling and bone acquisition'. Together they form a unique fingerprint.

Cite this