Ultrafine mapping of Dyscalc1 to an 80-kb chromosomal segment on chromosome 7 in mice susceptible for dystrophic calcification

• Published in: Physiological genomics Vol. 28; no. 2; pp. 203 - 212
• Main Authors: Aherrahrou, Zouhair, Doehring, Lars C, Kaczmarek, Piotr M, Liptau, Henrike, Ehlers, Eva-Maria, Pomarino, Andrea, Wrobel, Sandra, Gotz, Anika, Mayer, Bjoern, Erdmann, Jeanette, Schunkert, Heribert
• Format: Journal Article
• Language: English
• Published: United States Am Physiological Soc 17.01.2007
• Subjects: Animals; Calcinosis - genetics; Calcinosis - pathology; Cardiomyopathies - genetics; Cardiomyopathies - pathology; Chromosome Mapping - methods; Chromosomes, Mammalian - genetics; Female; Freezing; Gene Expression Profiling; Genetic Predisposition to Disease - genetics; Genotype; Heart Injuries - etiology; Heart Injuries - genetics; Mice; Mice, Inbred AKR; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred CBA; Mice, Inbred DBA; Mice, Inbred NZB; Mice, Inbred Strains; Polymorphism, Single Nucleotide; Quantitative Trait Loci - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism
• ISSN: 1094-8341; 1531-2267
• DOI: 10.1152/physiolgenomics.00133.2006

Medizinische Klinik II, University of Luebeck, Luebeck, Germany In mice, dystrophic cardiovascular calcification (DCC) is controlled by a major locus on proximal mouse chromosome 7 named Dyscalc1 . Here we present a strategy that combines in silico analysis, expression analysis, and extensive sequencing for ultrafine mapping of the Dyscalc1 locus. We subjected 15 laboratory mouse strains to freeze-thaw injury of the heart, and association with respective genotypes allowed condensation of the Dyscalc1 locus to 1 Mb. Within this region, 51 known and predicted genes were studied in DCC-susceptible C3H/He and DCC-resistant C57BL/6 mice with respect to mRNA expression in response to injury. Five genes displayed differential expression. Genotyping of seven novel single nucleotide polymorphisms (SNPs) within these genes revealed an 80-Kb region in NZB mice that were found positive for calcification though carrying otherwise alleles from DCC-resistant mice. This microheterogeneity in NZB mice was evolutionary conserved in all DCC-susceptible mouse strains and contains the genes EMP-3 , BC013491 , and Abcc6 (partially). The flanking SNPs are rs3703247 and NT_039420 .5_2757991. mRNA levels of EMP-3 were found to be upregulated in response to injury in both C57BL/6 and C3H/He mice. Sequencing of EMP-3 revealed an SNP leading to an amino acid substitution (p.T153I) that was found in all mouse strains susceptible for DCC but not in resistant strains such as C57BL/6 mice. Thus, the p.T153I changes might affect the biological function of EMP-3 gene product after injury. Using this combined approach, we ultrafine-mapped the Dyscalc1 locus to an 80-Kb region and identified EMP-3 as a new candidate gene for DCC. cardiovascular calcification; EMP-3; Abcc6