Dynamic regulatory interactions of Polycomb group genes: MEDEA autoregulation is required for imprinted gene expression in Arabidopsis.
The imprinted Arabidopsis Polycomb group (PcG) gene MEDEA (MEA), which is homologous to Enhancer of Zeste [E(Z)], is maternally required for normal seed development. Here we show that, unlike known mammalian imprinted genes, MEA regulates its own imprinted expression: It down-regulates the maternal allele around fertilization and maintains the paternal allele silent later during seed development. Autorepression of the maternal MEA allele is direct and independent of the MEA-FIE (FERTILIZATION-INDEPENDENT ENDOSPERM) PcG complex, which is similar to the E(Z)-ESC (Extra sex combs) complex of animals, suggesting a novel mechanism. A complex network of cross-regulatory interactions among the other known members of the MEA-FIE PcG complex implies distinct functions that are dynamically regulated during reproduction.
Baroux
Célia
C
Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, CH-8008 Zürich, Switzerland.
Gagliardini
Valeria
V
Page
Damian R
DR
Grossniklaus
Ueli
U
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D018392:Genomic Imprinting; D006706:Homeostasis; D012097:Repressor Proteins / Q000502:physiology; D012098:Reproduction; D012639:Seeds / Q000235:genetics* / Q000502:physiology
D029681:Arabidopsis Proteins; C118816:FIE protein, Arabidopsis; C111712:MEA protein, Arabidopsis; D012097:Repressor Proteins