title: Architecture of energy balance traits in emerging lines of the Collaborative Cross.
abstract: The potential utility of the Collaborative Cross (CC) mouse resource was evaluated to better understand complex traits related to energy balance. A primary focus was to examine if genetic diversity in emerging CC lines (pre-CC) would translate into equivalent phenotypic diversity. Second, we mapped quantitative trait loci (QTL) for 15 metabolism- and exercise-related phenotypes in this population. We evaluated metabolic and voluntary exercise traits in 176 pre-CC lines, revealing phenotypic variation often exceeding that seen across the eight founder strains from which the pre-CC was derived. Many phenotypic correlations existing within the founder strains were no longer significant in the pre-CC population, potentially representing reduced linkage disequilibrium (LD) of regions harboring multiple genes with effects on energy balance or disruption of genetic structure of extant inbred strains with substantial shared ancestry. QTL mapping revealed five significant and eight suggestive QTL for body weight (Chr 4, 7.54 Mb; CI 3.32-10.34 Mb; Bwq14), body composition, wheel running (Chr 16, 33.2 Mb; CI 32.5-38.3 Mb), body weight change in response to exercise (1: Chr 6, 77.7Mb; CI 72.2-83.4 Mb and 2: Chr 6, 42.8 Mb; CI 39.4-48.1 Mb), and food intake during exercise (Chr 12, 85.1 Mb; CI 82.9-89.0 Mb). Some QTL overlapped with previously mapped QTL for similar traits, whereas other QTL appear to represent novel loci. These results suggest that the CC will be a powerful, high-precision tool for examining the genetic architecture of complex traits such as those involved in regulation of energy balance.
authors.affiliation: Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA. wfmathes@med.unc.edu
authors.forename: Wendy Foulds
authors.initials: WF
authors.lastname: Mathes
authors.forename: David L
authors.initials: DL
authors.lastname: Aylor
authors.forename: Darla R
authors.initials: DR
authors.lastname: Miller
authors.forename: Gary A
authors.initials: GA
authors.lastname: Churchill
authors.forename: Elissa J
authors.initials: EJ
authors.lastname: Chesler
authors.forename: Fernando Pardo-Manuel
authors.initials: FP
authors.lastname: de Villena
authors.forename: David W
authors.initials: DW
authors.lastname: Threadgill
authors.forename: Daniel
authors.initials: D
authors.lastname: Pomp
mesh_terms: D000483:Alleles; D000704:Analysis of Variance; D000818:Animals; D050218:Body Fat Distribution; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics; D003433:Crosses, Genetic; D004435:Eating / Q000235:genetics / Q000502:physiology; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology*; D005838:Genotype; D015810:Linkage Disequilibrium; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000502:physiology; D010641:Phenotype; D010805:Physical Conditioning, Animal / Q000502:physiology; D040641:Quantitative Trait Loci; D012420:Running / Q000502:physiology; D018401:Sample Size