Genet. Sel. Evol. 38 (2006) 297-311
DOI: 10.1051/gse:2006005

Fatness QTL on chicken chromosome 5 and interaction with sex

Behnam Abasht^a, Frédérique Pitel^b, Sandrine Lagarrigue^a, Elisabeth Le Bihan-Duval^c, Pascale Le Roy^{a, d}, Olivier Demeure^a, Florence Vignoles^b, Jean Simon^c, Larry Cogburn^e, Sammy Aggrey^f, Alain Vignal^b and Madeleine Douaire<sup>a

a</sup>  UMR Inra-Agrocampus Génétique animale, 35042 Rennes, France
^b  Laboratoire de génétique cellulaire, Inra, 31326 Auzeville, France
^c  Station de recherches avicoles, Inra, 37380 Nouzilly, France
^d  SGQA, Inra, 78352 Jouy en Josas, France
^e  Department of Animal and Food Sciences, University of Delaware, Newark DE 19717, USA
^f  University of Georgia, Athens, GA 30602, USA

(Received 5 October 2005; accepted 8 December 2005; published online 26 April 2006)

Abstract - Quantitative trait loci (QTL) affecting fatness in male chickens were previously identified on chromosome 5 (GGA5) in a three-generation design derived from two experimental chicken lines divergently selected for abdominal fat weight. A new design, established from the same pure lines, produced 407 F2 progenies (males and females) from 4 F1-sire families. Body weight and abdominal fat were measured on the F₂ at 9 wk of age. In each sire family, selective genotyping was carried out for 48 extreme individuals for abdominal fat using seven microsatellite markers from GGA5. QTL analyses confirmed the presence of QTL for fatness on GGA5 and identified a QTL by sex interaction. By crossing one F1 sire heterozygous at the QTL with lean line dams, three recombinant backcross 1 (BC1) males were produced and their QTL genotypes were assessed in backcross 2 (BC2) progenies. These results confirmed the QTL by sex interaction identified in the F2 generation and they allow mapping of the female QTL to less than 8 Mb at the distal part of the GGA5. They also indicate that fat QTL alleles were segregating in both fat and lean lines.

Key words: meat-type chickens / quantitative trait loci / fatness QTL / QTL sex interaction

Correspondence and reprints: Madeleine.Douaire@rennes.inra.fr

© INRA, EDP Sciences 2006