Centre for Genetic Improvement of Livestock, University of Guelph, N1G 2W1, Guelph, Ontario, Canada.
Theor Appl Genet. 1992 Jul;84(3-4):323-9. doi: 10.1007/BF00229490.
Asymmetry in correlated responses to selection is expected when more than one cycle of selection is practised due to changes in genetic parameters produced by selection. In large populations, under the infinitesimal model these changes are due to linkage disequilibrium generated by selection and not to gene frequency changes. This study examines the conditions under which asymmetrical correlated responses are to be expected when an infinitesimal model is considered. Asymmetrical correlated responses in two traits in respect to which trait is selected are expected if the two traits have different heritabilities. Predicted asymmetry increases with the absolute value of the genetic correlation between the two traits, the difference between the two heritabilities, the intensity of selection and the number of generations of selection. Linkage disequilibrium generated by selection should be taken into account in explaining asymmetrical correlated responses observed in selection experiments.
当进行多次选择循环时，由于选择产生的遗传参数变化，预计会出现相关响应的不对称性。在大群体中，根据微效模型，这些变化是由于选择产生的连锁不平衡引起的，而不是由于基因频率的变化。本研究探讨了在考虑微效模型时预期出现不对称相关响应的条件。如果两个性状具有不同的遗传力，则选择的两个性状之间的两个性状的相关响应预期会出现不对称性。预测的不对称性随着两个性状之间的遗传相关性的绝对值、两个遗传力之间的差异、选择的强度和选择的世代数的增加而增加。在解释选择实验中观察到的不对称相关响应时，应考虑选择产生的连锁不平衡。
