Regulation of Imprinted Gene and Small RNA Expression in the Arabidopsis Endosperm
The Arabidopsis endosperm is an unique tissue to angiosperms, and is the main tissue where imprinting occurs. Using high-throughput sequencing we found 123 new imprinted genes and expect that the total number of imprinted genes present in the endosperm ranges from 200-500. From the 114 maternally expressed imprinted genes we found 29 genes which expression mechanism are controlled by DNA methylation and/or PcG activity. For the rest of imprinted genes and presumably the majority of p4-siRNAs, the maternal expression may be controlled by other mechanisms or use homolog of known imprinting proteins.