MEDEA takes control of its own imprinting.
Genomic imprinting is an essential epigenetic process that controls the size of seeds in flowering plants. In Arabidopsis, DEMETER activates the maternal copy of the imprinted MEDEA Polycomb gene. In this issue of Cell, Gehring et al. (2006) demonstrate that this activation involves DNA demethylation of MEDEA by DEMETER. Remarkably, they also find that silencing of the paternal MEDEA allele is independent of DNA methylation and is controlled by maternal expression of MEDEA itself.
Arnaud
Philippe
P
Institute of Molecular Genetics, CNRS UMR-5535 and the University of Montpellier II, 1919 route de Mende, 34090 Montpellier, France.
Feil
Robert
R
D000818:Animals; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics*; D019175:DNA Methylation; D018744:DNA, Plant / Q000235:genetics; D044127:Epigenesis, Genetic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018392:Genomic Imprinting; D008322:Mammals; D008957:Models, Genetic
D029681:Arabidopsis Proteins; D018744:DNA, Plant; C111712:MEA protein, Arabidopsis