Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  7
• Reference
  J:89623 Aherrahrou Z, et al., A locus on chromosome 7 determines dramatic up-regulation of osteopontin in dystrophic cardiac calcification in mice. Am J Pathol. 2004 Apr;164(4):1379-87
• ID
  MGI:3579881

Genes

Gene	Assay Type
Drsi	visible phenotype
D7Mit56	PCR
D7Mit230	PCR
Tgfb1	reported elsewhere

Notes

• Experiment
  The Spp1 gene on mouse Chromosome 5 shows strong expression at sites of cardiac calcification induced by freeze-thaw injury. Inbred strain C3H/HeNCrlBr is susceptible to dystrophic cardiac calcinosis (DCC) and exhibits 20-fold increased Ssp1 mRNA induction after freeze-thaw injury compared to DCC-resistant strain C57BL/6NCrlBr. A previously identified locus on mouse Chromosome 7 named Dyscalc1 (21 cM) shows linkage to the DCC phenotype.
  
  In this study, a congenic line named B6.C3-(D7Mit56-D7Mit230) was used to assess the effect of the Dyscalc1 locus on Ssp1 expression. The congenic carries C3H/HeNCrlBr-derived DNA between D7Mit56 (2.5 cM) and D7Mit230 (24.5 cM), which contains the Dyscalc1 locus, on a C57BL/6NCrlBr genetic background. Similar to the DCC-susceptible donor strain C3H/HeNCrlBr, the congenic exhibits DCC susceptibility and significantly increased Spp1 induction following cardiac injury. Since the congenic Spp1 locus is derived from background strain C57BL/6NCrlBr, this finding shows that DCC susceptibility is not controlled by Spp1. However, the locus between D7Mit56 and D7Mit230 appears to be a trans-activator of Spp1 expression and controls DCC susceptibility.
  
  A potential candidate gene found within the congenic interval is Tgfb1 (6.5 cM). Tgfb2 has been shown to induced Opn1 and shows greater induction in the necrotic tissues of C3H/He animals compared to C57BL/6 animals. Since Tgfb1 (6.5 cM) and Dyscalc1 (21 cM) map to different positions it is not clear if they represent the same underlying cause for cardiac injury related Opn1 induction. For this reason the locus between D7Mit56 and D7Mit230 is named Drsi (DCC-related Spp1 induction).