Results
author = "Pikaard, Craig S."
Transcription and Tyranny in the Nucleolus: The Organization, Activation, Dominance and Repression of Ribosomal RNA Genes.
Author(s) :
Pikaard, Craig S.
Description :
Repository :
Europe PubMed Central
Language(s) :
English
Epigenetic silencing of RNA polymerase I transcription: a role for DNA methylation and histone modification in nucleolar dominance
Description :
Nucleolar dominance is an epigenetic phenomenon that describes nucleolus formation around rRNA genes inherited from only one progenitor of an interspecific hybrid or allopolyploid. The phenomenon is widespread, occurring in plants, insects, amphibians, and mammals, yet its molecular basis remains un...
Repository :
Europe PubMed Central
Language(s) :
English
Extensive purification of a putative RNA polymerase I holoenzyme from plants that accurately initiates rRNA gene transcription in vitro
Description :
RNA polymerase I (pol I) is a nuclear enzyme whose function is to transcribe the duplicated genes encoding the precursor of the three largest ribosomal RNAs. We report a cell-free system from broccoli (Brassica oleracea) inflorescence that supports promoter-dependent RNA pol I transcription in vitro...
Repository :
Europe PubMed Central
Language(s) :
English
Restricted chromosomal silencing in nucleolar dominance
Description :
Failure of one parent's chromosomes to organize nucleoli in an
interspecific hybrid is an epigenetic phenomenon known as nucleolar
dominance. Selective gene silencing on a scale of millions of bp
is known to be involved, but the full extent to which nucleolus
organizer region (NOR)-bearing chrom...
Repository :
Europe PubMed Central
Language(s) :
English
RNA-Silencing Enzymes Pol IV and Pol V in Maize: More than one Flavor?
Description :
Repository :
Europe PubMed Central
Language(s) :
English
Transcriptional analysis of nucleolar dominance in polyploid plants: Biased expression/silencing of progenitor rRNA genes is developmentally regulated in Brassica
Description :
Nucleolar dominance is an epigenetic phenomenon that describes the formation of nucleoli around rRNA genes inherited from only one parent in the progeny of an interspecific hybrid. Despite numerous cytogenetic studies, little is known about nucleolar dominance at the level of rRNA gene expression in...
Repository :
Europe PubMed Central
Language(s) :
English
Gene dosage and stochastic effects determine the severity and direction of uniparental ribosomal RNA gene silencing (nucleolar dominance) in Arabidopsis allopolyploids
Description :
Nucleolar dominance is an epigenetic phenomenon in which one parental set of ribosomal RNA (rRNA) genes is silenced in an interspecific hybrid. In natural Arabidopsis suecica, an allotetraploid (amphidiploid) hybrid of Arabidopsis thaliana and Cardaminopsis arenosa, the A. thaliana rRNA genes are re...
Repository :
Europe PubMed Central
Language(s) :
English
Metal A and Metal B Sites of Nuclear RNA Polymerases Pol IV and Pol V Are Required for siRNA-Dependent DNA Methylation and Gene Silencing
Description :
Plants are unique among eukaryotes in having five multi-subunit nuclear RNA polymerases: the ubiquitous RNA polymerases I, II and III plus two plant-specific activities, nuclear RNA polymerases IV and V (previously known as Polymerases IVa and IVb). Pol IV and Pol V are not required for viability bu...
Repository :
Europe PubMed Central
Language(s) :
English
Heterochromatic siRNAs and DDM1 Independently Silence Aberrant 5S rDNA Transcripts in Arabidopsis
Description :
5S ribosomal RNA gene repeats are arranged in heterochromatic arrays (5S rDNA) situated near the centromeres of Arabidopsis chromosomes. The chromatin remodeling factor DDM1 is known to maintain 5S rDNA methylation patterns while silencing transcription through 5S rDNA intergenic spacers (IGS). We m...
Repository :
Europe PubMed Central
Language(s) :
English
RNA Polymerase V Functions in Arabidopsis Interphase Heterochromatin Organization Independently of the 24-nt siRNA-Directed DNA Methylation Pathway
Description :
In Arabidopsis, pericentromeric repeats, retroelements, and silenced rRNA genes are assembled into heterochromatin within nuclear structures known as chromocenters. The mechanisms governing higher-order heterochromatin organization are poorly understood but 24-nt small interfering RNAs (siRNAs) are ...
Repository :
Europe PubMed Central
Language(s) :
English