Genetical Research



Bayesian analyses of multiple epistatic QTL models for body weight and body composition in mice


NENGJUN YI a1a2, DENISE K. ZINNIEL a3, KYOUNGMI KIM a1, EUGENE J. EISEN a4, ALFRED BARTOLUCCI a1, DAVID B. ALLISON a1a2 and DANIEL POMP a5c1
a1 Department of Biostatistics, Section on Statistical Genetics, University of Alabama, Birmingham, AL 35294, USA
a2 Clinical Nutrition Research Center, University of Alabama, Birmingham, AL 35294, USA
a3 Department of Veterinary and Biomedical Sciences, University of Nebraska, Lincoln, NE 68583, USA
a4 Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA
a5 Departments of Nutrition, Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC 27599, USA

Article author query
yi n   [PubMed][Google Scholar] 
zinniel dk   [PubMed][Google Scholar] 
kim k   [PubMed][Google Scholar] 
eisen ej   [PubMed][Google Scholar] 
bartolucci a   [PubMed][Google Scholar] 
allison db   [PubMed][Google Scholar] 
pomp d   [PubMed][Google Scholar] 

Abstract

To comprehensively investigate the genetic architecture of growth and obesity, we performed Bayesian analyses of multiple epistatic quantitative trait locus (QTL) models for body weights at five ages (12 days, 3, 6, 9 and 12 weeks) and body composition traits (weights of two fat pads and five organs) in mice produced from a cross of the F1 between M16i (selected for rapid growth rate) and CAST/Ei (wild-derived strain of small and lean mice) back to M16i. Bayesian model selection revealed a temporally regulated network of multiple QTL for body weight, involving both strong main effects and epistatic effects. No QTL had strong support for both early and late growth, although overlapping combinations of main and epistatic effects were observed at adjacent ages. Most main effects and epistatic interactions had an opposite effect on early and late growth. The contribution of epistasis was more pronounced for body weights at older ages. Body composition traits were also influenced by an interacting network of multiple QTLs. Several main and epistatic effects were shared by the body composition and body weight traits, suggesting that pleiotropy plays an important role in growth and obesity.

(Published Online February 1 2006)
(Received August 18 2005)
(Revised November 29 2005)


Correspondence:
c1 Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA. Tel: +1 (919) 9660013. Fax: +1 (801) 3823686. e-mail: dpomp@unc.edu


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