title: Overlapping mouse subcongenic strains successfully separate two linked body fat QTL on distal MMU 2.
abstract: BACKGROUND
  Mouse chromosome 2 is linked to growth and body fat phenotypes in many mouse crosses. With the goal to identify the underlying genes regulating growth and body fat on mouse chromosome 2, we developed five overlapping subcongenic strains that contained CAST/EiJ donor regions in a C57BL/6J (hg/hg) background (hg is a spontaneous deletion of 500 Kb on mouse chromosome 10). To fine map QTL on distal mouse chromosome 2 a total of 1,712 F2 mice from the five subcongenic strains, plus 278 F2 mice from the HG2D founder congenic strain were phenotyped and analyzed. Interval mapping (IM) and composite IM (CIM) were performed on body weight and body fat traits on a combination of SNP and microsatellite markers, which generated a high-density genotyping panel.
  
  
  RESULTS
  Phenotypic analysis and interval mapping of total fat mass identified two QTL on distal mouse chromosome 2. One QTL between 150 and 161 Mb, Fatq2a, and the second between 173.3 and 175.6 Mb, Fatq2b. The two QTL reside in different congenic strains with significant total fat differences between homozygous cast/cast and b6/b6 littermates. Both of these QTL were previously identified only as a single QTL affecting body fat, Fatq2. Furthermore, through a novel approach referred here as replicated CIM, Fatq2b was mapped to the Gnas imprinted locus.
  
  
  CONCLUSIONS
  The integration of subcongenic strains, high-density genotyping, and CIM succesfully partitioned two previously linked QTL 20 Mb apart, and the strongest QTL, Fatq2b, was fine mapped to a ~2.3 Mb region interval encompassing the Gnas imprinted locus.
authors.affiliation: Department of Animal Science, University of California, Davis, CA, 95616-8521, USA. rodrigo.gularte@ulg.ac.be.|Current Address: Unit of Animal Genomics, GIGA - Research, Avenue de l'Hôpital 1, 4031, Sart-Tilman, Belgique. rodrigo.gularte@ulg.ac.be.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Gularte-Mérida
authors.affiliation: Center for Public Health Genomics, University of Virginia, Charlottesville, VA, 22908, USA. crf2s@virginia.edu.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Farber
authors.affiliation: Department of Animal Science, University of California, Davis, CA, 95616-8521, USA. ricardo.a.verdugo@gmail.com.|Current Address: Programa de Genética Humana ICBM, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago, Chile. ricardo.a.verdugo@gmail.com.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Verdugo
authors.affiliation: Department of Animal Science, University of California, Davis, CA, 95616-8521, USA. adislas@ucdavis.edu.
authors.forename: Alma
authors.initials: A
authors.lastname: Islas-Trejo
authors.affiliation: Department of Animal Science, University of California, Davis, CA, 95616-8521, USA. trfamula@ucdavis.edu.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Famula
authors.affiliation: Rowe Genetics Program and Department of Pediatrics, University of California, Davis, CA, 95616-8521, USA. chwarden@ucdavis.edu.
authors.forename: Craig H
authors.initials: CH
authors.lastname: Warden
authors.affiliation: Department of Animal Science, University of California, Davis, CA, 95616-8521, USA. jfmedrano@ucdavis.edu.
authors.forename: Juan F
authors.initials: JF
authors.lastname: Medrano
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D001835:Body Weight; D001921:Brain / Q000378:metabolism; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D005838:Genotype; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000378:metabolism; D010641:Phenotype; D011401:Promoter Regions, Genetic; D040641:Quantitative Trait Loci; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D014157:Transcription Factors