Detection of imprinting in two commercial pig populations

Genomic imprinting is an epigenetic phenomenon where the level of expression of alleles depends on their parental origin. On the molecular level, genomic imprinting is established by differential methylation of particular chromosomal regions which results in a parent-of-origin dependent expression of RNA (Feil and Berger, 2007). On the phenotypic level, imprinting is manifested through a contrast between the two heterozygote classes that exist for a genotype (A/a and a/A) (Hager et al., 2009).