Retinoblastoma makes its mark on imprinting in plants

[...]the predominant occurrence of imprinting in extra-embryonic structures might indicate a similar reproductive strategy in both taxa to correctly regulate embryo growth and development. Because extra-embryonic lineages do not contribute any genetic information to the offspring, it is likely that epigenetic mechanisms responsible for imprinting could evolve rapidly [2,3], without causing deleterious consequences to the offspring. Given the remarkable similarities in the recruitment of specific epigenetic machinery by mammals and plants, the question is: do plant imprints also passively lose methylation during the cell cycle through a similar process? [...]Arabidopsis RB and its associated WD-40 protein, MSI1, have only been implicated in the regulation of female gametophyte (embryo sac) and early seed development [19-22].