Identification of Polymorphisms of Fas Gene and Association Analysis in Hanwoo

Fas gene known to associate with intramuscular fat content in Korean cattle was selected for DNA marker development. Fas (APO-1, CD95), a member of the tumor necrosis factor (TNF) receptor superfamily, is a cell membrane protein that mediates apoptosis (programmed cell death). We discovered single nucleotide polymorphisms (SNPs) within Fas gene in order to develop novel DNA markers at genomic level. Of this gene to search for SNP, sequences of whole exon and 1kb range of both front and back of the gene using 24 cattle were determined by direct-sequencing methods. As a result, 16 SNPs in exon, 37 SNPs in intron and 2 SNPs in promoter region, a total of 55 SNPs were discovered. In these SNPs, thirty-one common polymorphic sites were selected considering their allele frequencies, haplotype-tagging status and Linkage Disequilibrium (LD) for genotyping in larger-scale subjects. Selected SNPs were confirmed genotype through SNaPshot method (n=274) and were examined for possible genetic association of Fas polymorphisms with carcass weight (CWT), eye muscle area (EMA), and backfat thickness (BF). So, the SNP have been identified significant g.-12T>G, g.1112T>G and g.32548T>C. These results suggest that polymorphism of Fas gene was associated with meat quality traits in Hanwoo.