Lack of an association between single nucleotide polymorphisms in the bovine leptin gene and intramuscular fat in Bos taurus cattle

Leptin contributes to the regulation of adiposity and metabolism, and single nucleotide polymorphisms (SNPs) in the leptin gene have been associated with intramuscular fat (IMF) levels in beef. Our objectives were to estimate the frequency of four SNPs in the leptin gene in nine purebred cattle (n = 430), to test for linkage disequilibrium and infer haplotypes, and to determine if individual genotypes or estimated haplotypes were associated with IMF values in crossbred cattle (n = 244). The four SNP loci were found to be in linkage disequilibrium and thus, the frequencies of each of the 16 possible haplotypes were inferred by maximum likelihood. No significant association between any individual SNP and haplotype was found with the divergent IMF values. Our results suggest that these SNPs are not influential on the divergent IMF levels in the crossbred population tested.