title: Disruption of the genomic imprint in trans with homologous recombination at Snrpn in ES cells.
abstract: In gene targeting studies of the Prader-Willi syndrome (PWS)/Angelman syndrome (AS) domain in mouse ES cells, we recovered only recombinants with the paternal allele for constructs at exons 2 or 3 of the imprinted, maternally silenced Snurf-Snrpn gene. These sites lie close to the imprinting center (IC) for this domain. In contrast, recombinants for Ube3a within the same imprinted domain were recovered with equal frequency on the maternal and paternal alleles. In addition, gene targeting of the paternal allele for Snurf-Snrpn resulted in partial or complete demethylation in trans with activation of expression for the previously silenced maternal allele. The imprint switching of the maternal allele in trans is not readily explained by competition for trans-acting factors and adds to a growing body of evidence indicating homologous association of oppositely imprinted chromatin domains in somatic mammalian cells.
authors.affiliation: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Ting-Fen
authors.initials: TF
authors.lastname: Tsai
authors.forename: Jan
authors.initials: J
authors.lastname: Bressler
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Jiang
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Beaudet
mesh_terms: D000483:Alleles; D017204:Angelman Syndrome / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D019175:DNA Methylation; D005091:Exons / Q000235:genetics; D018392:Genomic Imprinting / Q000235:genetics*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics; D011218:Prader-Willi Syndrome / Q000235:genetics; D011995:Recombination, Genetic; D013234:Stem Cells / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000235:genetics*
chemical_list: D009687:Nuclear Proteins; C445239:SNURF protein, human; C486713:SNURF protein, mouse; C471639:UBE3A protein, human; D044767:Ubiquitin-Protein Ligases