title: Genomic imprinting in plants: what makes the functions of paternal and maternal genes different in endosperm formation?
abstract: Genomic imprinting refers to the unequal expression of maternal and paternal alleles according to the parent of origin. This phenomenon is regulated by epigenetic controls and has been reported in placental mammals and flowering plants. Although conserved characteristics can be identified across a wide variety of taxa, it is believed that genomic imprinting evolved independently in animal and plant lineages. Plant genomic imprinting occurs most obviously in the endosperm, a terminally differentiated embryo-nourishing tissue that is required for seed development. Recent studies have demonstrated a close relationship between genomic imprinting and the development of elaborate defense mechanisms against parasitic elements during plant sexual reproduction. In this chapter, we provide an introductory description of genomic imprinting in plants, and focus on recent advances in our understanding of its role in endosperm development, the frontline of maternal and paternal epigenomes.
authors.affiliation: Kihara Institute for Biological Research, Yokohama City University, Kanagawa, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ohnishi
authors.affiliation: Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Ishikawa, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sekine
authors.affiliation: Kihara Institute for Biological Research, Yokohama City University, Kanagawa, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Kinoshita
mesh_terms: D000818:Animals; D056625:Endosperm / Q000235:genetics*; D044127:Epigenesis, Genetic; D018745:Genome, Plant; D018392:Genomic Imprinting; D006801:Humans; D010944:Plants / Q000235:genetics*; D012098:Reproduction / Q000235:genetics
keywords: DNA methylation; Endosperm; Epigenetics; Plant genomic imprinting; Polycomb repressive complex 2(PRC2); Sexual reproduction; Transposable elements (transposons)