title: Polycomb complexes and epigenetic states.
abstract: Important advances in the study of Polycomb Group (PcG) complexes in the past two years have focused on the role of this repressive system in programing the genome. Genome-wide analyses have shown that PcG mechanisms control a large number of genes regulating many cellular functions and all developmental pathways. Current evidence shows that, contrary to the classical picture of their role, PcG complexes do not set a repressed chromatin state that is maintained throughout development but have a much more dynamic role. PcG target genes can become repressed or be reactivated or exist in intermediate states. What controls the balance between repression and derepression is a crucial question in understanding development and differentiation in higher organisms.
authors.affiliation: Department of Molecular Biology and Biochemistry, Rutgers University, 604 Allison Road, Piscataway, NJ 08854, USA.
authors.forename: Yuri B
authors.initials: YB
authors.lastname: Schwartz
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Pirrotta
mesh_terms: D000818:Animals; D019175:DNA Methylation; D044127:Epigenesis, Genetic / Q000235:genetics*; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D046911:Macromolecular Substances / Q000378:metabolism; D010802:Phylogeny; D063146:Polycomb-Group Proteins; D034622:RNA Interference / Q000502:physiology; D050436:Regulatory Elements, Transcriptional / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D013045:Species Specificity
chemical_list: D046911:Macromolecular Substances; D063146:Polycomb-Group Proteins; D012097:Repressor Proteins