[Drosophila Fab-7 insulator effectively blocks polycomb-mediated repression in transgenic lines].
The bithorax complex (BX-C) genes have a regulatory region containing nine independent parasegment-specific enhancers. Inactivation of the enhancers is a result of Pc-mediated repression, which leads to the appearance of active and repressed domains. Active domains are supposed to be separated from the repressed domains by insulators on the domain boundaries. Three insulators were found in the BX-C by the ability to block enhancers intransgenic model systems. It is shown that one of these three well studied insulators, Fab-7, is able to protect the yellow gene transcription against the most powerful Polycomb-dependent silencer from the bxd regulatory domain of the Ultra-bithorax gene (Ubx). The barrier activity requires a region containing GAF-binding sites. Interestingly, the silencer used in the model system (1.5 kb PRE from the regulatory region of Ubx) recruits a transgenic construct with a frequency of up to 47% into genomic regions that completely repress the yellow gene expression.
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Kyrchanova
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Georgiev
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D018507:Gene Expression Regulation, Developmental; D038101:Insulator Elements / Q000235:genetics*; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics*; D063150:Polycomb Repressive Complex 1
D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; C115870:E(Pc) protein, Drosophila; C066770:Pc protein, Drosophila; D063150:Polycomb Repressive Complex 1