Research article

Genome-wide identification of quantitative trait loci in a cross between Hampshire and Landrace II: Meat quality traits

Ellen Markljung^{* 1} , Martin H Braunschweig^{* 2,3} , Peter Karlskov-Mortensen⁴ , Camilla S Bruun⁴ , Milena Sawera^4,5 , In-Cheol Cho^2,6 , Ingela Hedebro-Velander⁷ , Åsa Josell⁸ , Kerstin Lundström⁹ , Gertrud von Seth¹⁰ , Claus B Jørgensen⁴ , Merete Fredholm⁴ and Leif Andersson^1,2

¹Department of Medical Biochemistry and Microbiology, Uppsala University, Box 597, SE-751 24 Uppsala, Sweden

²Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 597, SE-751 24 Uppsala, Sweden

³Institute of Genetics, Vetsuisse Faculty, University of Berne, Switzerland

⁴Department of Animal and Veterinary Basic Sciences, Division of Genetics and Bioinformatics, Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark

⁵Department of Animal Science, Warsaw Agricultural University, Ciszewskiego 8, 02-786 Warsaw, Poland

⁶National Institute of Subtropical Agriculture, R.D.A., 175-6, O-deung dong, Jeju, 690-150, South Korea

⁷Quality Genetics, 244 82 Kävlinge, Sweden

⁸Ugglarps slakteri AB, PI 91, SE-231 96, Trelleborg, Sweden

⁹Department of Food Science, Swedish University of Agricultural Sciences, Box 7051, SE-750 07 Uppsala, Sweden

¹⁰Tetra Pak Research & Development AB, Ruben Rausings gata, SE-221 86 Lund, Sweden

author email corresponding author email* Contributed equally

BMC Genetics 2008, 9:22doi:10.1186/1471-2156-9-22

Published:	28 February 2008

Abstract

Background

Meat quality traits are important in pig breeding programs, but they are difficult to include in a traditional selection program. Marker assisted selection (MAS) of meat quality traits is therefore of interest in breeding programs and a Quantitative Trait Locus (QTL) analysis is the key to identifying markers that can be used in MAS. In this study, Landrace and Hampshire intercross and backcross families were used to investigate meat quality traits. Hampshire pigs are commonly used as the sire line in commercial pig breeding. This is the first time a pedigree including Hampshire pigs has been used for a QTL analysis of meat quality traits.

Results

In total, we analyzed 39 meat quality traits and identified eight genome-wide significant QTL peaks in four regions: one on chromosome 3, two on chromosome 6 and one on chromosome 16. At least two of the QTLs do not appear to have been detected in previous studies. On chromosome 6 we identified QTLs for water content in M. longissimus dorsi (LD), drip loss in LD and post mortem pH decline in LD. On chromosomes 3 and 16 we identified previously undetected QTLs for protein content in LD and for freezing and cooking loss respectively.

Conclusion

We identified at least two new meat quality trait QTLs at the genome-wide significance level. We detected two QTLs on chromosome 6 that possibly coincide with QTLs detected in other studies. We were also able to exclude the C1843T mutation in the ryanodine receptor (RYR1) as a causative mutation for one of the chromosome 6 QTLs in this cross.