Protein-Protein Interaction Network of Positively Selected Genes under Pig Domestication

The genetic basis of pig domestication - the number of genes targeted by artificial selection, how they are organized in a system, and how they interact with each other within a functional compartment - remains unclear. In this study, we detected signatures of directional selection during pig domestication and the properties of the network of genes that harbor the signatures. We traced the signatures of artificial selection in two layers: selection acting at the initial establishments of major domesticated breeds detected by population genetic differentiation and recent ongoing selection detected by strong haplotype structures within each breed. A genome-wide single-nucleotide polymorphism (SNP) analysis, based on whole genome resequencing, revealed potential domestication genes, that form a large protein-protein interaction network. Functional modules in the network, involved in behavior and development, reflected the genetic basis of pig domestication. The error-tolerance property of this network may support the enhancement of the evolution and robustness of fitness-related traits during pig domestication.