Polymorphism, linkage mapping, and association analysis with carcass traits of four porcine candidate genes selected from gene-expression profiles of Czech Large White and Wild Boar muscles

Abstract

Genes that are expressed in skeletal muscles may play a role in prenatal muscle development and postnatal muscle growth and can be considered candidates for economically important traits. Four porcine genes that were differentially expressed in skeletal muscles of Czech Large White and Wild Boar (SORT1, EMP3, IL18, and BTG2) were selected to search for polymorphism, linkage assignment, and association analysis with carcass traits. Through comparative sequencing of portions of the genes numerous polymorphisms were revealed (SORT1 – 21, EMP3 – 6, IL18 – 41, BTG2 – 9). Linkage analysis in a Meishan × Pietrain F₂ pedigree showed the positions of the genes relative to other genes and markers on the respective chromosomes – SORT1 on SSC4, EMP3 on SSC6, IL18 and BTG2 on SSC9. Preliminary association analysis in pig commercial crosses with selected SNPs showed associations with several carcass traits at nominal P value of < 0.05, which may indicate their involvement in muscle growth and fat deposition. The tested polymorphisms may not be causal for the associations, but they may be in linkage disequilibrium with causative mutations.