Quantitative trait loci (QTL) for lean body mass and body length in MRL/MPJ and SJL/J F(2) mice

Funct Integr Genomics. 2002 Aug;2(3):98-104. doi: 10.1007/s10142-002-0053-7. Epub 2002 Jul 3.


Studies on the genetic mechanisms involved in the regulation of lean body mass (LBM) in mammals are minimal, although LBM is associated with a competent immune system and an overall good (healthy) body functional status. In this study, we performed a high-density genome-wide scan using 633 (MRL/MPJ x SJL/J) F(2) intercross to identify the quantitative trait loci (QTL) involved in the regulation of LBM. We hypothesized that additional QTL can be identified using a different mouse cross (MRL/SJL cross). Ten QTL were identified for LBM on chromosomes (chrs) 2, 6, 7, 9,13 and 14. Of those ten, QTL on chrs 6, 7 and 14 were exclusive to LBM, while QTL on chrs 4 and 11 were exclusively body length. LBM QTL on chrs 2 and 9 overlap with those of size. Altogether, the ten LBM QTL explained 41.2% of phenotypic variance in F(2) mice. Five significantly interacting loci that may be involved in the regulation of LBM were identified and accounted for 24.4% of phenotypic variance explained by the QTL. Five epistatic interactions, contributing 22.9% of phenotypic variance, were identified for body length. Interacting loci on chr 2 may influence LBM by regulating body length. Therefore, epistatic interactions as well as single QTL effects play an important role in the regulation of LBM.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alleles
  • Animals
  • Body Constitution*
  • Body Weight*
  • Epistasis, Genetic
  • Female
  • Genotype
  • Male
  • Mice
  • Mice, Inbred Strains
  • Phenotype*
  • Quantitative Trait Loci*
  • Quantitative Trait, Heritable