直接与间接选择响应在提高断奶后生长速度的小鼠中的作用。

Direct and correlated responses to selection for increased postweaning gain in mice.

机构信息

Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, USA.

出版信息

Theor Appl Genet. 1974 Jan;44(6):272-7. doi: 10.1007/BF00278743.

Abstract

Mass selection for increased body weight gain from 21 to 42 days of age was practiced for 12 generations in four replicate lines of ICR-albino mice. Response to selection averaged 0.56±0.03 g. per generation. This response represented an increase of 7.0 genetic standard deviation units and 3.4 phenotypic standard deviation units in 12 generations. The realized heritability pooled over the four replicates was 0.24±0.02. Sizable positive correlated responses were found for 42 and 56-day weight and gain from 42 to 56 days. Much smaller positive correlated responses were noted for 12-day litter weight and 12-day individual weight. Neither litter size nor weaning weight were significantly altered by selection for increased postweaning gain. Reproductive efficiency measured as percent fertile matings declined significantly in the selected lines.

摘要

从 21 日龄到 42 日龄，对 ICR 白化小鼠的四个重复品系进行了 12 代的体重增重的大规模选择。选择的平均反应为每代 0.56±0.03 克。这一反应代表了在 12 代中增加了 7.0 个遗传标准差单位和 3.4 个表型标准差单位。四个重复中综合的实现遗传力为 0.24±0.02。在 42 日龄和 56 日龄体重以及从 42 日龄到 56 日龄的增重方面，发现了相当大的正相关反应。在 12 日龄窝重和 12 日龄个体体重方面，观察到的正相关反应要小得多。窝产仔数或断奶体重均未因选择增加断奶后增重而显著改变。繁殖效率（以可育交配的百分比衡量）在选择系中显著下降。