|Van Vleck, Lloyd|
Submitted to: Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/1999
Publication Date: N/A
Interpretive Summary: As models for farm livestock, lines of mice have been developed for high or low heat loss. Heat loss is a measure of energy expenditure or maintenance requirement. Markers for chromosomes of mice were used to find genes for major effects on heat loss as well as the most likely location on the chromosomes. Records (560) were from matings of crosses of selected lines that differed by 53% for heat loss relative to a control line. Interval analysis with 71 marker loci on 19 chromosomes was employed. Evidence was found for gene locations on chromosomes 1, 2, 3 and 7 that affected heat loss. Other gene locations were identified that influenced gonadal fat and liver, heart and body weight at different ages. The genetic material of mammals is much the same from species to species. Thus this study of traits that would be economic traits in farm livestock suggests that gene location for similar traits can be found in farm animals.
Technical Abstract: Energy balance is a complex trait with relevance to the study of human obesity and of maintenance energy requirements of livestock. The objective was to identify quantitative trait loci (QTL) influencing traits that contribute to variation in energy balance with mice as a model. Two resource populations were created from lines of mice differing in heat loss s(HLOSS) measured by direct calorimetry as an indicator of energy expenditure. The HB resource population originated from a cross between a non-inbred line selected for high HLOSS and an inbred line with low HLOSS. Significant evidence for QTL influencing HLOSS was found for Chromosomes 1, 2, 3 and 7. Significant evidence for QTL influencing gonadal fat, brown fat, liver, heart, and body weight were also identified. The F2 LH resource population originated from non-inbred lines of mice that had undergone divergent selection for HLOSS. Chromosomes 1 and 3 were evaluated. The QTL for HLOSS identified on Chromosome 1 in the HB population was confirmed in the LH population, although the effect was smaller. The presence of a QTL influencing six week weight was also confirmed. Suggestive evidence for additional QTL influencing HLOSS, percent subcutaneous fat, and percent heart was found for Chromosome 1.