A comprehensive analysis of QTL for abdominal fat and breast muscle weights on chicken chromosome 5 using a multivariate approach |
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| Authors: | G. Le Mignon F. Pitel H. Gilbert E. Le Bihan-Duval F. Vignoles O. Demeure S. Lagarrigue J. Simon L. A. Cogburn S. E. Aggrey M. Douaire P. Le Roy |
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| Affiliation: | INRA, UMR598 Génétique Animale, 35042 Rennes, France;. Agrocampus Rennes, UMR598 Génétique Animale, 35042 Rennes, France;. IFR140, Génétique Fonctionnelle, Agronomie et Santé, 35043 Rennes, France;. Institut Technique de l'Aviculture, ITAVI, 75008 Paris, France;. INRA, UMR444 Laboratoire de Génétique Cellulaire, 31326 Toulouse, France;. EMVT, UMR444 Laboratoire de Génétique Cellulaire, 31326 Toulouse, France;. INRA, UR337 Station de Génétique Quantitative et Appliquée, 78352 Jouy-en-Josas, France;. INRA, UR83 Unitéde Recherches Avicoles, 37380 Nouzilly, France;. Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717, USA;. Department of Poultry Science, University of Georgia, Athens, GA 30602, USA |
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| Abstract: | Quantitative trait loci (QTL) influencing the weight of abdominal fat (AF) and of breast muscle (BM) were detected on chicken chromosome 5 (GGA5) using two successive F2 crosses between two divergently selected 'Fat' and 'Lean' INRA broiler lines. Based on these results, the aim of the present study was to identify the number, location and effects of these putative QTL by performing multitrait and multi-QTL analyses of the whole available data set. Data concerned 1186 F2 offspring produced by 10 F1 sires and 85 F1 dams. AF and BM traits were measured on F2 animals at slaughter, at 8 (first cross) or 9 (second cross) weeks of age. The F0, F1 and F2 birds were genotyped for 11 microsatellite markers evenly spaced along GGA5. Before QTL detection, phenotypes were adjusted for the fixed effects of sex, F2 design, hatching group within the design, and for body weight as a covariable. Univariate analyses confirmed the QTL segregation for AF and BM on GGA5 in male offspring, but not in female offspring. Analyses of male offspring data using multitrait and linked-QTL models led us to conclude the presence of two QTL on the distal part of GGA5, each controlling one trait. Linked QTL models were applied after correction of phenotypic values for the effects of these distal QTL. Several QTL for AF and BM were then discovered in the central region of GGA5, splitting one large QTL region for AF into several distinct QTL. Neither the 'Fat' nor the 'Lean' line appeared to be fixed for any QTL genotype. These results have important implications for prospective fine mapping studies and for the identification of underlying genes and causal mutations. |
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| Keywords: | chicken fatness linked QTL multivariate analysis QTL detection |
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