Quantitative trait loci (QTL) for lean body mass and body length in MRL/MPJ and SJL/J F(2) mice.
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.
Masinde
Godfred L
GL
Molecular Genetics Division, Musculoskeletal Disease Center, J.L. Pettis VA Medical Center and Loma Linda University, 11201 Benton Street (151), CA 92357, USA.
Li
Xinmin
X
Gu
Weikuan
W
Davidson
Heather
H
Hamilton-Ulland
Melanie
M
Wergedal
Jon
J
Mohan
Subburaman
S
Baylink
David J
DJ
D000483:Alleles; D000818:Animals; D001824:Body Constitution; D001835:Body Weight; D004843:Epistasis, Genetic; D005260:Female; D005838:Genotype; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010641:Phenotype; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable