1. Association of a missense mutation in the bovine leptin gene with carcass fat content and leptin mRNA levels
- Author
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Carolyn Fitzsimmons, F. C. Buchanan, T. D. Thue, Andrew G. Van Kessel, D. C. Winkelman-Sim, and Sheila M. Schmutz
- Subjects
Male ,Adipose tissue ,Exon ,Gene Frequency ,fat ,Genotype ,Missense mutation ,Genetics(clinical) ,lcsh:SF1-1100 ,Genetics ,0303 health sciences ,education.field_of_study ,Leptin ,Homozygote ,digestive, oral, and skin physiology ,Exons ,04 agricultural and veterinary sciences ,General Medicine ,marbling ,Phenotype ,Adipose Tissue ,Body Composition ,medicine.medical_specialty ,lcsh:QH426-470 ,Molecular Sequence Data ,Population ,Mutation, Missense ,Biology ,Polymorphism, Single Nucleotide ,leptin ,03 medical and health sciences ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,Allele ,education ,Allele frequency ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Base Sequence ,obese ,Research ,0402 animal and dairy science ,040201 dairy & animal science ,lcsh:Genetics ,[SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics ,Endocrinology ,Amino Acid Substitution ,cattle ,Animal Science and Zoology ,lcsh:Animal culture ,Microsatellite Repeats - 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.
- Published
- 2002
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