Box 2 | Genomic selection
From the following article:
Mapping genes for complex traits in domestic animals and their use in breeding programmes
Michael E. Goddard & Ben J. Hayes
Nature Reviews Genetics 10, 381-391 (June 2009)
doi:10.1038/nrg2575
A large sample of animals is measured for the trait and genotyped for markers. The genotypes can be represented by a variable (x), which takes the values 0 or 1 or 2 corresponding to one of the homozygotes, the heterozygote or the other homozygote. The statistical analysis of the reference population estimates effects for each marker (w), and hence a prediction equation can be generated that combines all the marker genotypes with their effects to predict the breeding value of each animal. This prediction equation can then be applied to a group of animals that have genotypes but not phenotypes, and the estimated breeding values calculated from this can be used to select the best animals for breeding.
