Genomic Imprinting: Parental Control of Gene Expression in Higher Plants

In flowering plants, insects, and mammals, some autosomal genes are uniparentally expressed in a parent-of-origin-specific manner due to epigenetic "marks" that differ depending on whether an allele is of maternal or paternal origin. This epigenetic phenomenon is known as genomic imprinting. Recently, large numbers of candidate-imprinted genes have been identified in F1 hybrid seeds of three plant species, Arabidopsis thaliana, Oryza sativa, and Zea mays. This provides new opportunities for further validation of true imprinted genes, deciphering mechanisms of epigenetic regulation via genomic imprinting, and for understanding the evolutionary dynamics of imprinting in plant lineages. In particular, we discuss the challenges and approaches to demonstration that any particular candidate-imprinted genes are indeed imprinted in the triploid endosperm of hybrid F1 seeds that are genetically chimeric. This edition first published 2013