Free Access
Genet. Sel. Evol.
Volume 34, Number 2, March-April 2002
Page(s) 193 - 210

Genet. Sel. Evol. 34 (2002) 193-210
DOI: 10.1051/gse:2002003

A further look at quantitative trait loci affecting growth and fatness in a cross between Meishan and Large White pig populations

Raquel Quintanillaa, Denis Milanb and Jean-Pierre Bidanela

a  Station de génétique quantitative et appliquée, Institut national de la recherche agronomique, 78352 Jouy-en-Josas Cedex, France
b  Laboratoire de génétique cellulaire, Institut national de la recherche agronomique, 31326 Castanet Tolosan Cedex, France

(Received 23 April 2001; accepted 15 October 2001)

A detailed quantitative trait locus (QTL) analysis of growth and fatness data from a three generation experimental cross between Large White (LW) and Meishan (MS) pig breeds was carried out to search for sex $\times$ QTL interactions, imprinting effects and multiple linked QTLs. A total of 530 F 2 males and 573 F 2 females issued from 6 F 1 boars and 23 F 1 sows were typed for a total of 137 markers covering the entire porcine genome. Nine growth traits and three backfat thickness measurements were analysed. All analyses were performed using line cross regression procedures. A QTL with sex-specific expression was revealed in the proximal region of chromosome 8, although some confusion between herd and sex effects could not be discarded. This previously undetected QTL affected male growth during the fattening period, with a favourable additive effect of the LW allele. The analyses also revealed the presence of two linked QTLs segregating on chromosome 1, affecting growth traits during the post-weaning period. The first QTL, previously detected using a single QTL model, was located at the end of the q arm of chromosome 1 and had a favourable MS allele. The second QTL had a favourable LW allele and was located in the proximal extremity of the q arm of chromosome 1. Suggestive genomic imprinting was found in the distal region of chromosome 9 affecting growth during the fattening period.

Key words: pig / growth / sex-QTL interaction / imprinting / linked QTLs

Correspondence and reprints: Jean-Pierre Bidanel

© INRA, EDP Sciences 2002