Ultrafine mapping of Dyscalc1 to an 80-kb chromosomal segment on chromosome 7 in mice susceptible for dystrophic calcification.
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.
Aherrahrou
Zouhair
Z
Medizinische Klinik II, University of Luebeck, Luebeck, Germany. aherrazou@o2online.de
Doehring
Lars C
LC
Kaczmarek
Piotr M
PM
Liptau
Henrike
H
Ehlers
Eva-Maria
EM
Pomarino
Andrea
A
Wrobel
Sandra
S
Götz
Anika
A
Mayer
Bjoern
B
Erdmann
Jeanette
J
Schunkert
Heribert
H
D000818:Animals; D002114:Calcinosis / Q000235:genetics* / Q000473:pathology; D009202:Cardiomyopathies / Q000235:genetics* / Q000473:pathology; D002874:Chromosome Mapping / Q000379:methods*; D033481:Chromosomes, Mammalian / Q000235:genetics*; D005260:Female; D005615:Freezing; D020869:Gene Expression Profiling; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006335:Heart Injuries / Q000209:etiology / Q000235:genetics; D051379:Mice; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D008814:Mice, Inbred NZB; D008815:Mice, Inbred Strains; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger