Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/1999
Publication Date: N/A
Interpretive Summary: Uncoupling proteins are mitochondrial proteins that have a role in determining the amount of metabolic energy going into high energy chemical bonds verses the amount going into heat. Uncoupling protein 1 (UCP1) is expressed only in brown adipose tissue and has been well characterized for its involvement in regulating body temperature (rodent models.) Recently, two other uncoupling proteins, UCP2 and UCP3 have been discovered. UCP3 i highly expressed in muscle and has the potential of being very important in overall energy balance since muscle is a large fraction of total body mass. Also, UCP3 expression is increased by thyroxin which is well known for its role in maintaining metabolic rate, energy requirements, and heat production. In livestock, the biochemical and genetic basis for maintenance energy requirements and feed efficiency are not well characterized. In future genome wide searches focusing on energy metabolism in cattle, it will be important to include as many candidate genes as possible. To this end, we have mapped UCP2 and UCP3 to bovine chromosome 15 and defined five single nucleotide polymorphisms in the UCP3 gene which are useful as markers.
Technical Abstract: Two recently described uncoupling proteins, UCP2 and UCP3, may have important roles in determining feed conversion and/or maintenance energy requirements in livestock. Sequence was determined for the entire coding region and four of the six introns for UCP3. A partial cDNA sequence was obtained for UCP2. Radiation hybrid mapping was used to place UCP3 on BTA15, a chromosome previously shown to harbor a locus influencing meat tenderness. In order to place UCP3 in the existing linkage map, five single nucleotide polymorphisms (SNPs) were developed. Linkage analysis using one of five SNPs was used to place UCP3 between 53.1 and 53.5 cM. No recombination was detected between UCP3 and IDVGA10, IDVGA32, and INRA145. The sequence of PCR products from a single BAC amplified with primers specific for either UCP2 or UCP3 indicate that UCP2 and UCP3 are separated by < 200 kb.