title: Regulation of the new Arabidopsis imprinted gene AtBMI1C requires the interplay of different epigenetic mechanisms.
abstract: Recently, it has been shown that plants contain homologs to the animal Polycomb repressive complex 1 (PRC1) components BMI1 and RING1A/B. In Arabidopsis, there are three BMI1-like genes, two of which, AtBMI1A and B, are required during post-embryonic plant growth to repress embryonic traits and allow cell differentiation. However, little is known about the third BMI1-like gene, AtBMI1C. In this work, we show that AtBMI1C is only expressed during endosperm and stamen development. AtBMI1C is an imprinted gene expressed from the maternal allele in the endosperm but biallelically expressed in stamen. We found that the characteristic expression pattern of AtBMI1C is the result of a complex epigenetic regulation that involves CG DNA methylation, RNA-directed non-CG DNA methylation (RdDM), and PcG activity. Our results show the orchestrated interplay of different epigenetic mechanisms in regulating gene expression throughout development, shedding light on the current hypotheses for the origin and mechanism of imprinting in plant endosperm.
authors.affiliation: Centre for Organismal Studies Heidelberg, Department of Biodiversity and Plant Systematics, University of Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Bratzel
authors.forename: Chao
authors.initials: C
authors.lastname: Yang
authors.forename: Alexandra
authors.initials: A
authors.lastname: Angelova
authors.forename: Gema
authors.initials: G
authors.lastname: López-Torrejón
authors.forename: Marcus
authors.initials: M
authors.lastname: Koch
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: del Pozo
authors.forename: Myriam
authors.initials: M
authors.lastname: Calonje
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D056625:Endosperm / Q000235:genetics / Q000378:metabolism; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018392:Genomic Imprinting