Genomic Imprinting in Plants: A Predominantly Maternal Affair

Arabidopsis GLAUCEpromotes fertilization-independent endosperm development and expression of paternally inherited alleles

“…glc suppresses autonomous endosperm development of mea and msi1 in the prefertilization central cell The absence of endosperm development in glc seeds is in contrast to the autonomous and over-proliferated endosperm phenotypes of the gametophytic maternal effect fis class mutants mea, fis2, fie and msi1 (reviewed by Grossniklaus, 2005). This prompted us to investigate the genetic interactions between glc and these FIS class genes in the pre-fertilization central cell.…”

“…Although the zygote/embryo is not required for autonomous endosperm development as known from the fis class mutants (reviewed by Chaudhury and Berger, 2001) (Gehring et al, 2004;Grossniklaus, 2005), unfertilized endosperm proliferation in seeds having fertilized embryos suggests that, when present, the zygote/early embryo triggers a signal to the unfertilized central cell resulting in partial endosperm development (Nowack et al, 2006). Moreover, when the egg cell alone is fertilized, endosperm development of the unfertilized central cell is further promoted by the mea mutation (Nowack et al, 2006;Nowack et al, 2007).…”

“…The gametophytic maternal effect of the FIS genes (reviewed by Grossniklaus, 2005) and of the large class of MATERNAL EFFECT EMBRYO ARREST (MEE) genes (Pagnussat et al, 2005), of which some display this early preferentially maternal expression (Jullien et al, 2006b;Kinoshita et al, 1999;Luo et al, 2000;Vielle-Calzada et al, 1999) (Köhler et al, 2003a;Köhler et al, 2003b;Makarevich et al, 2006), or positively, as demonstrated by the activation of maternal MEA by maternal DEMETER (Choi et al, 2002;Choi et al, 2004). Moreover, the regulatory mechanism of the maternal genome crosses its own genome boundary to affect the paternal genome.…”

Female gametophytic cell specification and seed development require the function of the putativeArabidopsisINCENP orthologWYRD

“…Although genetic and molecular approaches have identified many factors involved in male and female gametophyte development (for reviews, see Borg et al, 2009;Brukhin et al, 2005;Dresselhaus and Marton, 2009;Kägi and Gross-Hardt, 2007;Liu and Qu, 2008;Sundaresan and Alandete-Saez, 2010;Yadegari and Drews, 2004;Yang et al, 2010) and maternal effects on seed formation (for reviews, see Berger and Chaudhury, 2009;Grossniklaus, 2005;Huh et al, 2008;North et al, 2010), the molecular processes underlying cell specification and differentiation are still poorly understood. Only a small number of genes involved in the cellular differentiation of gametophytic cell types has been described.…”

“…The prolifera (prl) mutant disrupting an S-phase-specific DNA replication licensing factor affects mitotic divisions late during female gametogenesis and produces maternal effects on embryogenesis (Springer et al, 2000). Maternal effects play an important role in embryonic development in most animal species (for reviews, see Glover, 2005;Li et al, 2010;Lindeman and Pelegri, 2010) but have only recently been investigated in higher plants (for reviews, see Grossniklaus, 2005;Grossniklaus and Schneitz, 1998;Rodrigues et al, 2010). Like prl, about half of the gametophytic mutants in Arabidopsis display gametophytic maternal effects early in seed development (Moore et al, 2002;Pagnussat et al, 2005), including the well-studied FERTILIZATION-INDEPENDENT SEED (FIS) class genes (Chaudhury et al, 1997;Guitton et al, 2004;Köhler et al, 2003;Luo et al, 1999;Ohad et al, 1996;Ohad et al, 1999) and several cell cycle genes (Andreuzza et al, 2010;Pignocchi et al, 2009).…”