A comprehensive genome-wide scan for parent-of-origin expressed genes in the pig clarifies the conservation landscape of genomic imprinting

Altogether, our results provide an atlas of parent-of-origin expressed genes in the pig, making it the most documented species for genomic imprinting after humans and rodents. Our findings indicate weak conservation of this mechanism across species and tissues, suggesting a small number of core imprinted genes shared across eutherians and another imprinted genes that seem specific to species or tissues. These latter parent-of-origin expressed genes may have been subjected to evolutionary forces that have determine their imprinting status in either a livestock-specific or a tissue-specific manner.