Institute of Animal Genetics, University of Edinburgh, West Mains Road, EH9 3JN, Edinburgh, Scotland.
Theor Appl Genet. 1985 Nov;71(1):44-51. doi: 10.1007/BF00278252.
To examine the effect of selection on levels of heterosis, crosses were made between three groups of six lines of mice, one group unselected (controls) and the other two selected for high (large lines) and low (small lines) 6-week body weight, respectively. The coefficient of inbreeding of each line was about 0.60. Each line was crossed reciprocally to one line from each of the parental groups, as well as producing purebred progeny. Heterosis for 3-week weight, 6-week weight and 3-6 week gain averaged 0.0%, 2.4% and 4.2%, respectively, and was higher for males than for females. Heterosis was more extensive in crosses involving large or control lines than in crosses with small lines. There was no detectable heterosis in several measures of developmental rate, such as age at vaginal opening. Food conversion efficiency and carcass composition were measured on a sample of the animals. Food consumption, gonadal fat pad weight, and hindquarters weight, each expressed as a proportion of body weight, exhibited -4.0%, 5.6%, and 2.3% heterosis, respectively.
为了研究选择对杂种优势水平的影响，我们对三组共 6 个品系的老鼠进行了杂交，一组未选择（对照组），另外两组分别选择高（大品系）和低（小品系）6 周体重。每条线的近交系数约为 0.60。每条线都与来自亲本组的一条线进行了相互杂交，同时还产生了纯系后代。3 周体重、6 周体重和 3-6 周增重的杂种优势平均值分别为 0.0%、2.4%和 4.2%，雄性的杂种优势高于雌性。大品系或对照组的杂交杂种优势比小品系的杂交杂种优势更为广泛。在几个发育速度的衡量指标中，如阴道开口年龄，都没有发现杂种优势。对一部分动物进行了食物转化率和体成分的测量。以体重为基准，食物摄入量、性腺脂肪垫重量和后躯重量的杂种优势分别为-4.0%、5.6%和 2.3%。
