Linked Life Data

9268020

Source:http://linkedlifedata.com/resource/pubmed/id/9268020

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-9-18
pubmed:abstractText
In wheat-rye hybrids the nucleolus organizer regions (NORs), the sites of ribosomal RNA genes, from rye are suppressed. Wheat and wheat-rye hybrid genetic stocks containing different numbers of wheat and rye nucleolus organizers, as well as addition lines and rye-barley hybrids, were used in Southern hybridization experiments to determine the cause of nucleolar dominance and suppression in cereal hybrids. Based on the use of restriction endonucleases that cleave near the ends of the spacer unit and an additional, methylation-sensitive enzyme, HpaII, which does not recognize the CCGG restriction site if the internal C is methylated, an indirect method of assaying NOR expression was established. The results indicated that cleavage by the HpaII enzyme of the rye NOR sequences, is reduced when major NORs from other cereals were present. The reduction in the number of rye rRNA genes containing an unmethylated CCGG site in the promoter was associated with the suppression of the rye nucleolus. These results are consistent with a model in which promoter and upstream regulatory repeats of ribosomal RNA genes compete for limited concentrations of regulatory proteins, and genes that are methylated at key binding sites fail to engage these regulatory proteins and thus remain inactive.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:volume
255
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
294-301
pubmed:dateRevised
2008-8-29
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Cytosine methylation and nucleolar dominance in cereal hybrids.
pubmed:affiliation
United States Department of Agriculture, Agricultural Research Service, University of Missouri, Columbia 65211, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't