title: maternally expressed gene1 Is a novel maize endosperm transfer cell-specific gene with a maternal parent-of-origin pattern of expression.
abstract: Growth of the maize (Zea mays) endosperm is tightly regulated by maternal zygotic and sporophytic genes, some of which are subject to a parent-of-origin effect. We report here a novel gene, maternally expressed gene1 (meg1), which shows a maternal parent-of-origin expression pattern during early stages of endosperm development but biallelic expression at later stages. Interestingly, a stable reporter fusion containing the meg1 promoter exhibits a similar pattern of expression. meg1 is exclusively expressed in the basal transfer region of the endosperm. Further, we show that the putatively processed MEG1 protein is glycosylated and subsequently localized to the labyrinthine ingrowths of the transfer cell walls. Hence, the discovery of a parent-of-origin gene expressed solely in the basal transfer region opens the door to epigenetic mechanisms operating in the endosperm to regulate certain aspects of nutrient trafficking from the maternal tissue into the developing seed.
authors.affiliation: Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom. jose.gutierrez@plants.ox.ac.uk
authors.forename: Jose F
authors.initials: JF
authors.lastname: Gutiérrez-Marcos
authors.forename: Liliana M
authors.initials: LM
authors.lastname: Costa
authors.forename: Corinne
authors.initials: C
authors.lastname: Biderre-Petit
authors.forename: Bouchaib
authors.initials: B
authors.lastname: Khbaya
authors.forename: Donal M
authors.initials: DM
authors.lastname: O'Sullivan
authors.forename: Mark
authors.initials: M
authors.lastname: Wormald
authors.forename: Pascual
authors.initials: P
authors.lastname: Perez
authors.forename: Hugh G
authors.initials: HG
authors.lastname: Dickinson
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D005966:Glucuronidase / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified; D011487:Protein Conformation; D012098:Reproduction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000235:genetics*; D015053:Zygote / Q000502:physiology
chemical_list: D006023:Glycoproteins; D010940:Plant Proteins; D005966:Glucuronidase