Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2006
Publication Date: 12/1/2006
Citation: Coulibaly, I., Danzmann, R., Palti, Y., Vallejo, R.L., Gahr, S.A., Yao, J., Rexroad III, C.E. 2006. Mapping of genes in a region associated with upper temperature tolerance in rainbow trout. Animal Genetics 37(6):598-599.
Interpretive Summary: The identification and characterization of genes influencing aquaculture production traits will facilitate genetic improvement. In 2003, researchers at the University of Guelph identified chromosome regions in salmonids which affect upper temperature tolerance. We report genetic mapping of two uncoupling protein 2 genes, UCP2A and UCP2B, close to these chromosomal regions. Although the map locations of these genes exclude them as candidates affecting this trait, their proximity to other genes will facilitate the use of whole genome sequences from other fishes to identify the genes responsible.
Technical Abstract: Uncoupling proteins (UCP) are located in the inner mitochondrial membrane, where they uncouple respiration from oxidative phosphorylation. In mammals, the UCP2 gene is expressed ubiquitously and is involved in a variety of physiological processes including energy balance, fat metabolism and immune function. Characterization of UCP2 genes in rainbow trout including association with quantitative trait loci (QTL) will increase our understandings of their biochemical functions and their chromosomal evolution in vertebrates. We previously identified two rainbow trout UCP2 genes which are differentially expressed. The identification of two UCP2 genes in rainbow trout was anticipated due to an evolutionarily recent genome duplication event common to most salmonids. UCP2A and UCP2B were assigned to female linkage groups RT-20 and RT-9, respectively. This agrees with previous results suggesting homology between RT-9 and RT-20. Both of these chromosome regions have been associated with QTL for upper temperature tolerance in salmonids. Although the map locations of these genes exclude them as positional candidates for this trait, their proximity to these QTL will facilitate comparative mapping with other fishes.