DOI: 10.1051/gse:2001120

Genet. Sel. Evol. 33 (2001) 289-309

Detection of quantitative trait loci for growth and fatness in pigs

Jean-Pierre Bidanel^a, Denis Milan^b, Nathalie Iannuccelli^b, Yves Amigues^c, Marie-Yvonne Boscher^c, Florence Bourgeois^c, Jean-Claude Caritez^d, Joseph Gruand^e, Pascale Le Roy^a, Hervé Lagant^a, Raquel Quintanilla^a, Christine Renard^f, Joël Gellin^b, Louis Ollivier^a and Claude Chevalet<sup>b

a</sup>  Institut national de la recherche agronomique, Station de génétique quantitative et appliquée, 78352 Jouy-en-Josas Cedex, France
^b  Institut national de la recherche agronomique, Laboratoire de génétique cellulaire, 31326 Castanet Tolosan Cedex, France
^c  Institut national de la recherche agronomique, Labogéna, 78352 Jouy-en-Josas Cedex, France
^d  Institut national de la recherche agronomique, Domaine expérimental du Magneraud, 17700 Surgères, France
^e  Institut national de la recherche agronomique, Station expérimentale de sélection porcine, 86480 Rouillé, France
^f  Institut national de la recherche agronomique, Laboratoire de radiobiologie et d'étude du génome, 78352 Jouy-en-Josas Cedex, France

(Received 27 October 2000; accepted 11 January 2001)

Abstract
A quantitative trait locus (QTL) analysis of growth and fatness data from a three-generation experimental cross between Meishan (MS) and Large White (LW) pig breeds is presented. Six boars and 23 F1 sows, the progeny of six LW boars and six MS sows, produced 530 F2 males and 573 F2 females. Nine growth traits, i.e. body weight at birth and at 3, 10, 13, 17 and 22 weeks of age, average daily gain from birth to 3 weeks, from 3 to 10 weeks and from 10 to 22 weeks of age, as well as backfat thickness at 13, 17 and 22 weeks of age and at 40 and 60 kg live weight were analysed. Animals were typed for a total of 137 markers covering the entire porcine genome. Analyses were performed using two interval mapping methods: a line-cross (LC) regression method where founder lines were assumed to be fixed for different QTL alleles and a half-/full-sib (HFS) maximum likelihood method where allele substitution effects were estimated within each half-/full-sib family. Both methods revealed highly significant gene effects for growth on chromosomes 1, 4 and 7 and for backfat thickness on chromosomes 1, 4, 5, 7 and X, and significant gene effects on chromosome 6 for growth and backfat thickness. Suggestive QTLs were also revealed by both methods on chromosomes 2 and 3 for growth and 2 for backfat thickness. Significant gene effects were detected for growth on chromosomes 11, 13, 14, 16 and 18 and for backfat thickness on chromosome 8, 10, 13 and 14. LW alleles were associated with high growth rate and low backfat thickness, except for those of chromosome 7 and to a lesser extent early-growth alleles on chromosomes 1 and 2 and backfat thickness alleles on chromosome 6.

Key words: pig / gene mapping / quantitative trait locus / growth / fatness

Correspondence and reprints: Jean-Pierre Bidanel
    e-mail: bidanel@dga.jouy.inra.fr

© INRA, EDP Sciences 2001