Gomez-Raya L, Gibson J P
Centre for Genetic Improvement of Livestock, Animal and Poultry Science, University of Guelph, Ont., Canada.
Genome. 1993 Jun;36(3):433-9. doi: 10.1139/g93-059.
Identification of allelic variants with economic importance is feasible via molecular genetic techniques. This information can be used to increase the frequency of favourable alleles in dairy cattle. The effect of selection on the genotype within families in the early stages of life is examined. Three different strategies are considered: (1) random mating of bull sires with bull dams and with cows, with embryo selection of young bulls and all cows; (2) random mating of bull sires with bull dams, with embryo selection of young bulls only; (3) minimizing or avoiding matings between homozygotes for the unfavourable allele, with embryo selection of young bulls. Selection strategies assume the use of reproductive technologies such as embryo transfer to produce large family sizes for within-family selection to be practiced. All the three strategies increase the frequency of the favourable allele rapidly. Strategy 1 gives the fastest increase in the frequency of the favourable allele. The increase in the frequency of the favourable allele is slower under random mating (strategy 2) than under a negative assortative mating (strategy 3). This is a novel example of increased selection response with negative assortative mating.
通过分子遗传技术识别具有经济重要性的等位基因变异是可行的。这些信息可用于提高奶牛中有利等位基因的频率。研究了在生命早期阶段选择对家系内基因型的影响。考虑了三种不同的策略：（1）公牛父亲与公牛母亲以及母牛随机交配，对年轻公牛和所有母牛进行胚胎选择；（2）公牛父亲与公牛母亲随机交配，仅对年轻公牛进行胚胎选择；（3）尽量减少或避免不利等位基因纯合子之间的交配，对年轻公牛进行胚胎选择。选择策略假定使用胚胎移植等生殖技术来产生大家庭规模，以便进行家系内选择。所有这三种策略都能迅速提高有利等位基因的频率。策略1使有利等位基因频率增加最快。在随机交配（策略2）下，有利等位基因频率的增加比在负选型交配（策略3）下要慢。这是负选型交配增加选择反应的一个新例子。
