Association of a missense mutation in the bovine leptin gene with carcass fat content and leptin mRNA levels

Abstract

-Previously, we have shown that alleles of the BM1500 microsatellite, located 3.6 kb downstream of the leptin gene in cattle, were associated with carcass fat measures in a population of 154 unrelated beef bulls. Subsequently, a cytosine (C) to thymine (T) transition that encoded an amino acid change of an arginine to a cysteine was identified in exon 2 of the leptin gene. A PCR-RFLP was designed and allele frequencies in four beef breeds were correlated with levels of carcass fat. The T allele was associated with fatter carcasses and the C allele with leaner carcasses. The frequencies of the SNP alleles among breeds indicated that British breeds have a higher frequency of the T allele whereas the continental breeds have a higher occurrence of the C allele. A ribonuclease protection assay was developed to quantify leptin mRNA in a separate group of animals selected by genotype. Animals homozygous for thymine expressed higher levels of leptin mRNA. This may suggest that the T allele, which adds an extra cysteine to the protein, imparts a partial loss of biological function and hence could be the causative mutation.leptin / cattle / obese / fat / marbling

Genetic polymorphism of two genes associated with carcass trait in Egyptian buffaloes

“…Polymorphisms have been reported in the coding regions of the LEP gene that show considerable associations with feed intake [30,29,39], carcass merit [4,37,25], serum leptin concentration [31] and milk quantity and quality [5,32,34,8] in cattle.…”

“…Leptin has been considered as a candidate gene for performance, carcass and meat quality traits in beef cattle [17,4,29].…”

“…Genetic polymorphisms in the coding regions of the leptin gene in cattle have been associated with serum leptin concentration [31], feed intake [30,39], milk yield [32,5] and body fat [4,37].…”

The Influence of Single Nucleotide Polymorphism in the Leptin Gene on Serum Energy Metabolism Parameters in Cattle

“…When fat mass enlarges leptin is synthesized and secreted by the white fat cells, thus providing information to the hypothalamus about the excessive amount of fat deposits (Schwarz et al, 1996). Buchanan et al (2002) found, that higher leptin mRNA expression was in the cattle homozygous for the thymine (T) allele. This substitution having major biological effect.…”

“…The main role of leptin could be to help animals to adapt to period of undernutrition. Indeed, the rapid decrease in leptinemia in underfeed animals could be an acute signal to stimulate refeeding behavior and glucocorticoid secretion, to decrease thyroid activity, energy expenditure, insulin sensitivity and protein synthesis and to block reproduction (Chilliard et al, 2005). The leptin gene is located on bovine chromosome 4 (BTA4) (Buchanan et al, 2002) and consists of 3 exon, with exon 2 and 3 containing the protein coding region (Tian et al, 2013).…”