Linked Life Data

16037066

Source:http://linkedlifedata.com/resource/pubmed/id/16037066

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2005-8-22
pubmed:abstractText
The mouse insulin-like growth factor II receptor (Igf2r) gene and its antisense transcript Air are reciprocally imprinted in most tissues, but in the brain, Igf2r is biallelically expressed despite the imprinted Air expression. To investigate the molecular mechanisms of such brain-specific relaxation of Igf2r imprinting, we analyzed its expression and epigenetic modifications in neurons, glial cells and fibroblasts by the use of primary cortical cell cultures. In glial cells and fibroblasts, Igf2r was maternally expressed and Air was paternally expressed, whereas in the primary cultured neurons, Igf2r was biallelically expressed and Air was not expressed. In the differentially methylated region 2 (DMR2), which includes the Air promoter, allele-specific DNA methylation, differential H3 and H4 acetylation and H3K4 and K9 di-methylation were maintained in each cultured cell type. In DMR1, which includes the Igf2r promoter, maternal-allele-specific DNA hypomethylation, histones H3 and H4 acetylation and H3K4 di-methylation were apparent in glial cells and fibroblasts. However, in neurons, biallelic DNA hypomethylation and biallelic histones H3 and H4 acetylation and H3K4 di-methylation were detected. These data indicate that lack of reciprocal imprinting of Igf2r and Air in the brain results from neuron-specific relaxation of Igf2r imprinting associated with neuron-specific histone modifications in DMR1 and lack of Air expression. Our observation of biallelic Igf2r expression with no Air expression in neurons sheds light on the function of Air as a critical effector in Igf2r silencing and suggests that neuron-specific epigenetic modifications related to the lineage determination of neural stem cells play a critical role in controlling imprinting by antisense transcripts.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0964-6906
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2511-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Neuron-specific relaxation of Igf2r imprinting is associated with neuron-specific histone modifications and lack of its antisense transcript Air.
pubmed:affiliation
Department of Human Genetics, Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't