Linked Life Data

3116270

Source:http://linkedlifedata.com/resource/pubmed/id/3116270

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1987-11-20
pubmed:abstractText
Sequence data from regions of five vertebrate vitellogenin genes were used to examine the frequency, distribution, and mutability of the dinucleotide CpG, the preferred modification site for eukaryotic DNA methyltransferases. The observed level of the CpG dinucleotide in all five genes was markedly lower than that expected from the known mononucleotide frequencies. CpG suppression was greater in introns than in exons. CpG-containing codons were found to be avoided in the vitellogenin genes, but not completely despite the redundancy of the genetic code. Frequency and distribution patterns of this dinucleotide varied dramatically among these otherwise closely related genes. Dense clusters of CpG dinucleotides tended to appear in regions of either functional or structural interest (e.g., in the transposon-like Vi-element of Xenopus) and these clusters contained 5-methylcytosine (5 mC). 5 mC is known to undergo deamination to form thymidine, but the extent to which this transition occurs in the heavily methylated genomes of vertebrates and its contribution to CpG suppression are still unclear. Sequence comparison of the methylated vitellogenin gene regions identified C----T and G----A substitutions that were found to occur at relatively high frequencies. The predicted products of CpG deamination, TpG and CpA, were elevated. These findings are consistent with the view that CpG distribution and methylation are interdependent and that deamination of 5 mC plays an important role in promoting evolutionary change at the nucleotide sequence level.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0022-2844
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
107-15
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
The distribution of the dinucleotide CpG and cytosine methylation in the vitellogenin gene family.
pubmed:affiliation
Department of Neurochemistry, University of London, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't