Encontrados 6 documentos, a visualizar página 1 de 1
Relationships between transcription, silver staining and chromatin organization...
Caperta, A.; Neves, Nuno; Viegas, Wanda; Pikaard, Craig S.; Preuss, SashaSummary. The nucleolar organizer regions (NORs) are composed of hundreds of rRNA genes, typically spanning several megabases. Cytologically, NORs include regions that are highly condensed and regions that are decondensed, the latter corresponding to regions at which associated proteins stain intensively with silver (Ag-NORs) and where active rRNA gene transcription is thought to occur. To test the relationship ...
Postembryonic establishment of megabase-scale gene silencing in nucleolar domin...
Silva, Manuela; Viegas, Wanda; Pontes, Olga; Lawrence, Richard; Preuss, Sasha; Costa-Nunes, Pedro; Earley, Keith; Neves, Nuno; Pikaard, CraigNucleolar dominance is an epigenetic phenomenon in plant and animal genetic hybrids that describes the expression of 45S ribosomal RNA genes (rRNA genes) inherited from only one progenitor due to the silencing of the other progenitor’s rRNA genes. rRNA genes are tandemly arrayed at nucleolus organizer regions (NORs) that span millions of basepairs, thus gene silencing in nucleolar dominance occurs on a scale se...
Erasure of histone acetylation by Arabidopsis HDA6 mediates large-scale gene si...
Silva, Manuela; Viegas, Wanda; Earley, Keith; Lawrence, Richard; Pontes, Olga; Reuther, Rachel; Enciso, Angel; Neves, Nuno; Gross, MichaelNucleolar dominance describes the silencing of one parental set of ribosomal RNA (rRNA) genes in a genetic hybrid, an epigenetic phenomenon that occurs on a scale second only to X-chromosome inactivation in mammals. An RNA interference (RNAi) knockdown screen revealed that the predicted Arabidopsis histone deacetylase, HDA6, is required for rRNA gene silencing in nucleolar dominance. In vivo, derepression of si...
A concerted DNA methylation/histone methylation switch regulates rDNA gene dosa...
Silva, Manuela; Viegas, Wanda; Lawrence, Richard J.; Early, Keith; Pontes, Olga; Chen, Z.; Neves, Nuno; Pikaard, Craig.S.Eukaryotes regulate the effective dosage of their ribosomal RNA (rRNA) genes, expressing fewer than half of the genes at any one time. Likewise, genetic hybrids displaying nucleolar dominance transcribe rRNA genes inherited from one parent but silence the other paraental set.We show that rRNA gene dosage control and nucleolar dominance utilize a common mechanism
Chromosomal locus rearrangements are a rapid response to formation of the allot...
Silva, Manuela; Viegas, Wanda; Pontes, Olga; Neves, Nuno; Lewis, Michelle S.; Madlung, Andreas; Comai, Luca; Pikaard, CraigAllopolyploidy is a significant evolutionary process, resulting in new species with diploid or greater chromosome complements derived from two or more progenitor species. We examined the chromosomal consequences of genomic merger in Arabidopsis suecica, the allotetraploid hybrid of Arabidopsis thaliana and Arabidopsis arenosa. Fluorescence in situ hybridization with centromere, nucleolus organizer region (NOR),...
Natural variation in nucleolar dominance reveals relationship between nucleolus...
Silva, Manuela; Viegas, Wanda; Pontes, Olga; Lawrence, Richard; Neves, Nuno; Lee, Jae-Hyeok; Chen, Z.; Pikaard, CraigIn genetic hybrids, nucleolus formation on chromosomes inherited from only one parent is the epigenetic phenomenon, nucleolar dominance. By using Arabidopsis suecica, the allotetraploid hybrid of Arabidopsis thaliana and Arabidopsis arenosa, natural variation in nucleolar dominance was found to occur, providing a unique opportunity to examine homologous nucleolus organizer regions (NORs) in their active and ina...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||