2003/11/24 by Tetsu Kinoshita, Asuka Miura, Yeonhee Choi +5 · 1 voice · 4 citations
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Epigenetics and DNA Methylation #Genetic Syndromes and Imprinting #Plant Molecular Biology Research
paper · doi:10.1126/science.1089835
The Arabidopsis FWA gene was initially identified from late-flowering epigenetic mutants that show ectopic FWA expression associated with heritable hypomethylation of repeats around transcription starting sites. Here, we show that wild-type FWA displays imprinted (maternal origin-specific) expression in endosperm. The FWA imprint depends on the maintenance DNA methyltransferase MET1, as is the case in mammals. Unlike mammals, however, the FWA imprint is not established by allele-specific de novo methylation. It is established by maternal gametophyte-specific gene activation, which depends on a DNA glycosylase gene, DEMETER. Because endosperm does not contribute to the next generation, the activated FWA gene need not be silenced again. Double fertilization enables plants to use such "one-way" control of imprinting and DNA methylation in endosperm.