Genetics Selection Evolution (Jan 2002)

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

  • Winkelman-Sim Dianne C,
  • Thue Tracey D,
  • Van Kessel Andrew G,
  • Fitzsimmons Carolyn J,
  • Buchanan Fiona C,
  • Schmutz Sheila M

DOI
https://doi.org/10.1186/1297-9686-34-1-105
Journal volume & issue
Vol. 34, no. 1
pp. 105 – 116

Abstract

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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.

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