The development and application of genomic selection as a new breeding paradigm

• A significant gap exists between demand based on population growth and the current trajectory of yield; this is a point of leverage for genomics. • Although traditional breeding methods have been effective in selecting for animals with easy-to-measure production traits, these methods have essentially “hit an asymptote,” and more difficult-to-measure (and often more important) traits cannot effectively be selected for using traditional methods. • The race to sequence the first human genome, and, subsequently, the race to enable routine resequencing of tens, if not hundreds of thousands, of additional human genomes, has resulted in a 100 million fold decrease in DNA sequencing prices since 1990. Animal genome sequencing has benefitted from this. • Sequencing and resequencing of economically important livestock species has resulted in the discovery of millions upon millions of single nucleotide polymorphisms. These single nucleotide polymorphisms are being deployed in massively parallel fashion on DNA microarrays, enabling genome-wide association studies to identify genotype-phenotype correlations for both simple and, more important, complex traits. • Driven by ever-increasing reductions in the cost of measuring genetic variation, we are entering a new era in which the information from these genome-wide association studies will be utilized effectively in routine testing using genomic selection. Genomic selection holds promise for more widespread adoption than marker-assisted selection because it lacks the requirement of prior knowledge of alleles or marker positions of loci and the requirement that marker-assisted selection must be implemented within families.