Cis and trans determinants of epigenetic silencing by Polycomb repressive complex 2 in Arabidopsis

Molecular machinery known as Polycomb repressive complex 2 (PRC2) is known to be responsible for silencing the expression of different genes by modifying the genome to shut down gene expression. Here the authors demonstrate for the first time, that the recruitment of PRC2 to such regions that are silenced is performed through the action of patterns in DNA sequence around the genes that are turned off. They identify regions throughout the genome silenced by PRC2, use algorithmic predictions to identify distinct DNA patterns in these regions, and then show the sufficiency of identified sequences for silencing by PRC2 by inserting the identified patterns into the genome and showing that they recruit PRC2 and silence the synthetic marker gene introduced. This discovery opens new lines of research and potential for manipulating gene expression in plants through subtle modifications to the DNA surrounding genes in order to influence expression without introducing transgenic material from other species or making extensive genomic changes.