Linked Life Data

10319870

Source:http://linkedlifedata.com/resource/pubmed/id/10319870

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-5-25
pubmed:databankReference
pubmed:abstractText
Altering cytosine methylation by genetic means leads to a variety of developmental defects in mice, plants and fungi. Deregulation of cytosine methylation also has a role in human carcinogenesis. In some cases, these defects have been tied to the inheritance of epigenetic alterations (such as chromatin imprints and DNA methylation patterns) that do not involve changes in DNA sequence. Using a forward genetic screen, we identified a gene (DDM1, decrease in DNA methylation) from the flowering plant Arabidopsis thaliana required to maintain normal cytosine methylation patterns. Additional ddm1 alleles (som4, 5, 6, 7, 8) were isolated in a selection for mutations that relieved transgene silencing (E.J.R., unpublished data). Loss of DDM1 function causes a 70% reduction of genomic cytosine methylation, with most of the immediate hypomethylation occurring in repeated sequences. In contrast, many low-copy sequences initially retain their methylation in ddm1 homozygotes, but lose methylation over time as the mutants are propagated through multiple generations by self-pollination. The progressive effect of ddm1 mutations on low-copy sequence methylation suggests that ddm1 mutations compromise the efficiency of methylation of newly incorporated cytosines after DNA replication. In parallel with the slow decay of methylation during inbreeding, ddm1 mutants accumulate heritable alterations (mutations or stable epialleles) at dispersed sites in the genome that lead to morphological abnormalities. Here we report that DDM1 encodes a SWI2/SNF2-like protein, implicating chromatin remodelling as an important process for maintenance of DNA methylation and genome integrity.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1061-4036
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
94-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Maintenance of genomic methylation requires a SWI2/SNF2-like protein.
pubmed:affiliation
Department of Biology, Washington University, St. Louis, Missouri 63130, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't