Product of a dosage-sensitive gene that contributes to the maintenance of paternally and maternally imprinted gene expression in the endosperm in order to balance parental contributions. Underlies postzygotic reproductive isolation by promoting triploid seed arrest in a genetic dosage-dependent manner, thus being a component of postzygotic interploidy hybridization barriers. Paternally imprinted expression in the endosperm. Suppressor of the triploid seed abortion phenotype observed in osd1 and jas-3 mutants, thus leading to enlarged and somewhat fertile triploid seeds production characterized by abnormally normalized parental imprinted genes expression. In Greek mythology, 'Admetos' was one of Jason's companions Argonauts in his quest for the Golden Fleece. Product of a paternally expressed imprinted gene (PEG).