Linked Life Data

8400126

Source:http://linkedlifedata.com/resource/pubmed/id/8400126

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1993-11-15
pubmed:abstractText
In several plant systems expression of structurally intact genes may be silenced epigenetically when a transgenic construct increases the copy number of DNA sequences. Here we report epigenetic silencing in Arabidopsis lines containing transgenic inserts of defined genetic structure, all at the same genomic locus. These comprise an allelic series that includes a single copy of the primary insert, which carries repeated drug resistance transgenes, and a set of its derivatives, which as a result of recombination within the insert carry different numbers and alleles of resistance genes. Although the drug resistance genes remained intact, both the primary and some recombinant lines nevertheless segregated many progeny that were partly or fully drug-sensitive because of silencing. As in other systems silencing was reversible, and correlated with decreased steady-state mRNA and increased DNA methylation. Each different number and combination of genes, on the same or different (i.e., homologous) chromosomes, conditioned its own idiosyncratic segregation pattern. Strikingly, lines with a single gene segregated only a few slightly drug-sensitive progeny whereas multi-gene lines segregated many highly sensitive progeny, indicating dependence of silencing at this locus on repeated sequences. This argues strongly against explanations based on antisense RNA, but is consistent with explanations based on ectopic DNA pairing. One possibility is that silencing reflects the interaction of paired homologous DNA with flanking heterologous DNA, which induces condensation of chromatin into a non-transcribable state.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0167-4412
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1067-85
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Epigenetic repeat-induced gene silencing (RIGS) in Arabidopsis.
pubmed:affiliation
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.