Moody D E, Pomp D, Nielsen M K
Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
Genet Res. 1997 Dec;70(3):225-35. doi: 10.1017/s0016672397003017.
Mouse populations differing in metabolic rate have been developed through selection for high (MH) and low (ML) heat loss (HLOSS), along with randomly selected controls (MC). Objectives of this study were to (a) compare MH, ML and MC lines for HLOSS and correlated traits of feed intake, body composition and organ weights; (b) compare three widely used inbred mouse lines with MH, ML and MC for the same traits; and (c) investigate potential genotype by diet interaction resulting from feeding diets differing in fat percentage. Heat loss (kcal/day) of MH and ML mice differed by 37% of the mean and remained significant (33%) when HLOSS was expressed on a fat-free mass basis. MH mice consumed more energy than ML with a greater difference in mice fed high-fat compared with standard diets (27% vs 13.9%). Despite greater energy consumption, MH mice were leaner than ML with a difference in total body fat percentage of 40%. The greatest difference in HLOSS between selection and inbred lines was between MH and C57BL/6J (BL), which differed by 26.3%. MH and BL mice also differed in energy intake (15.5%). Body composition of BL mice was similar to MH when fed a standard diet, but similar to ML when fed a high-fat diet. Crosses between MH and ML or between MH and BL would be useful to investigate the genetic regulation of, and identify quantitative trait loci influencing HLOSS, energy intake and body composition. Feeding of a high-fat diet may allow diet-specific loci influencing body composition to be identified in MH and BL lines.
通过对高（MH）低（ML）热损失（HLOSS）进行选择，以及随机选择对照（MC），培育出了代谢率不同的小鼠群体。本研究的目的是：（a）比较MH、ML和MC品系在HLOSS以及采食量、身体组成和器官重量等相关性状方面的差异；（b）比较三个广泛使用的近交系小鼠与MH、ML和MC在相同性状上的差异；（c）研究因饲喂脂肪百分比不同的日粮而产生的潜在基因型与日粮的相互作用。MH和ML小鼠的热损失（千卡/天）相差平均水平的37%，当以去脂体重为基础表示HLOSS时，差异仍很显著（33%）。与ML相比，MH小鼠消耗更多能量，在饲喂高脂日粮而非标准日粮的小鼠中差异更大（27%对13.9%）。尽管能量消耗更多，但MH小鼠比ML小鼠更瘦，总体脂肪百分比相差40%。选择品系和近交系之间HLOSS的最大差异存在于MH和C57BL/6J（BL）之间，相差26.3%。MH和BL小鼠在能量摄入方面也存在差异（15.5%）。饲喂标准日粮时，BL小鼠的身体组成与MH相似，但饲喂高脂日粮时与ML相似。MH与ML之间或MH与BL之间的杂交对于研究HLOSS、能量摄入和身体组成的遗传调控以及鉴定影响这些性状的数量性状位点将是有用的。饲喂高脂日粮可能有助于在MH和BL品系中鉴定影响身体组成的日粮特异性位点。
