Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  13
• Reference
  J:115910 Nakanishi R, et al., Secreted frizzled-related protein 4 is a negative regulator of peak BMD in SAMP6 mice. J Bone Miner Res. 2006 Nov;21(11):1713-21
• ID
  MGI:3694110

Genes

Gene	Assay Type
Pbd2	visible phenotype
Sfrp4	reported elsewhere

Notes

• Experiment
  Pbd2, a QTL associated with peak bone density, maps to 14.5 cM on mouse Chromosome 13. This locus was further refined using a congenic subline derived from P6.P2-Pbd2^b. The congenic subline is called P6.P2-13 and carries a 2.4 Mb interval derived from SAMP2 (a high bone density strain) on the genetic background of SAMP6 (an osteoporotic strain). The congenic interval extends from 17.46 Mb to 19.86 Mb. The right femurs of male congenic and SAMP6 animals were phenotyped at 4 months of age.
  
  Male P6.P2-13 animals exhibit increased bone volume at the metaphysis, increased cortical thickness at the diaphysis, and significantly increased periosteal mineralizing surface compared to male SAMP6 animals. Eleven genes map to the 2.4 Mb congenic interval. Sfrp4 (7 cM) is a candidate gene in this region. In vitro mRNA assay showed significantly increased Sfrp4 expression in SAMP6 cultured osteoblasts compared to P6.P2-13 cultured osteoblasts. Analysis SAMP2 and SAMP6 sequences detected a conservative polymorphism inthe Sfrp4 coding region and 14 nucleotide polymorphism in the putative promoter region. The congenic region of P6.P2-13 is syntenic to human Chromosome 17p14, a region associated with bone mineral density in humans.