Jones L D, Nielsen M K, Britton R A
Department of Animal Science, University of Nebraska, Lincoln 68583-0908.
J Anim Sci. 1992 Oct;70(10):2999-3006. doi: 10.2527/1992.70102999x.
Genetic variation for liver mass (LM), body mass (BM), and liver:body mass (LM/BM) was examined for outbred populations of laboratory mice. Liver mass and body mass data were collected on 170 pureline sires at 12 wk of age, representing four outbred stocks of laboratory mice; 523 of their male and female two-way-cross progeny at 9 or 12 wk; and 214 four-way-cross offspring at 12, 14, or 16 wk. Genetic differences for LM, BM, and LM/BM were found among the base sire lines and between two-way crosses. Heritabilities and genetic correlations for LM, BM, LM/BM, and LM/MBM (MBM = BM.75) were estimated using offspring-sire regression within and across characteristics. Estimates of heritabilities and genetic correlations were also derived from full-sib covariances in the two-way-cross generation. Heritability estimates pooled over all analyses were .53, .54, .36, and .40 for LM, BM, LM/BM, and LM/MBM, respectively. Body mass was highly genetically correlated (.87) with LM and lowly correlated with LM/BM. Previous research has indicated possible positive relationships between LM/BM and maintenance energy requirements in mature, nonlactating, nonpregnant animals. A selection index was developed for increasing BM but restricting genetic change in LM to zero. Selection using this index would be 40% as efficient in increasing BM as selection on BM alone but may hold maintenance energy requirements at a stable level.
对远交群的实验小鼠进行了肝脏质量（LM）、体重（BM）以及肝脏与体重之比（LM/BM）的遗传变异研究。收集了170只12周龄纯系父本的肝脏质量和体重数据，这些父本代表了四种远交群实验小鼠；还收集了它们523只9周或12周龄的雌雄双向杂交后代以及214只12周、14周或16周龄的四向杂交后代的数据。在基础父本系之间以及双向杂交后代之间发现了LM、BM和LM/BM的遗传差异。利用子代-父本回归对LM、BM、LM/BM和LM/MBM（MBM = BM.75）的遗传力和遗传相关性进行了估计，同时考虑了不同性状之间的关系。遗传力和遗传相关性的估计值也来自双向杂交世代的全同胞协方差。综合所有分析得出的遗传力估计值，LM、BM、LM/BM和LM/MBM分别为0.53、0.54、0.36和0.40。体重与肝脏质量高度遗传相关（0.87），与肝脏与体重之比低度相关。先前的研究表明，在成熟、非泌乳、非怀孕动物中，肝脏与体重之比与维持能量需求之间可能存在正相关关系。开发了一个选择指数，用于增加体重同时将肝脏质量的遗传变化限制为零。使用该指数进行选择在增加体重方面的效率仅为单独选择体重时的40%，但可能使维持能量需求保持在稳定水平。
