ARS | Publication request: FINE MAPPING OF GENES REGULATING HEAT LOSS IN MICE

Submitted to: Animal Genetics International Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2002
Publication Date: August 1, 2002
Citation: Elo, K., Nielsen, M., Van Vleck, L.D., Pomp, D. 2002. Fine mapping of genes regulating heat loss in mice [proceedings]. Animal Genetics International Conference, Gottingen, Germany, p. 165.

Technical Abstract: Three mapping populations have been produced from lines of mice that have undergone 16 generations of divergent selection for high and low heat loss using direct calorimetry. Two populations consisted of F2 intercrosses originating from either outbred (MH x ML, n=560) or inbred (IH x IL, n=640) high and low selection lines. The IH x IL F2 animals were further intermated to produce an advanced intercross line (AIL) that has been phenotyped at F11 (n=2,080). The main aims of this study are to identify QTL underlying energy balance and body composition and, using fine-mapping results from the AIL in conjunction with the human and mouse whole-genome sequences, identify candidate polygenes affecting these traits. Maintenance heat loss (kcal/kg 0.75/day) and feed intake (g/kg 0.75/day), body weights (3 and 6 wks and at tissue harvest) and tissue weights (brown adipose, subcutaneous and gonadal fat depots, liver and heart) were measured in all three populations. Total body fat percentage was estimated in the IH x IL F2 (using chemical extraction) and in the AIL at F11 (using dual-energy X-ray absorptiometry). Microsatellite markers have been genotyped in the MH x ML (n=149) and IH x IL (n=92) F2 populations. Summaries of phenotypic evaluation and initial QTL mapping results in the F2 intercrosses will be presented. This study will facilitate enhanced understanding of the polygenic genetic architecture of energy balance and body composition.