Abstract：The high-density single nucleotide polymorphism(SNP) genotyping platform allows genome wide association studies (GWAS) in pigs. In this GWAS, 355 pigs from a Large White(Sus scrofa)×Minzhu(S. scrofa) intercross population were genotyped using the Illumina Porcine SNP 60K BeadChip, and phenotyped for lean meat weight (LMW) after slaughtered at age of (240±7) d. Association tests between the trait and the SNPs were performed via GWAS using the mixed model and Regression-Genomic Control (GRAMMAR-GC) approach. This GWAS revealed 14 SNPs which showed chromosome-wide significant (P<9.63e-06, SSC1; P<2.37e-05, SSC2; P<1.56e-05, SSC14) association with LWM. On SSC1, two SNPs ALGA0010777 and ALGA0010788, which were located at 285 030 256 and 285 276 856 bp, showed significant association with LWM. Ten significant SNPs were mapped to distal end of SSC2, where the known major gene IGF2 for muscle mass QTL was located. The remainder two SNPs ASGA0065444 and ASGA0065455, which were located at 99 627 980 and 100 078 535 bp on SSC14, were associated with the LWM significantly. The present GWAS results revealed SNPs and candidate genes for LWM in pigs, and the molecular mechanism of LWM difference between Chinese indigenous pig breed and Western commercial pig breed is initially clarified
