Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-2-19
pubmed:abstractText
The mouse genome experiences a large decrease in net 5-methylcytosine between fertilization and implantation; de novo methylation brings 5-methylcytosine to adult somatic cell levels between implantation and gastrulation. Very little is known of the regulation of demethylation or de novo methylation. Levels of the one known form of DNA methyltransferase are very high in early embryos, but the enzyme is localized to the cytoplasm during most of preimplantation development. We show here that DNA methyltransferase is found exclusively in nuclei of the conceptus after implantation, and that nuclei of proximal decidual cells are free of detectable DNA methyltransferase. High levels of DNA methyltransferase were seen in all tissues, including the developing nervous system, of 9.5- to 12.5-day embryos. The large maternal stores of DNA methyltransferase become limiting prior to embryonic day 9.5, as shown by barely detectable immunostaining in 9.5-day embryos homozygous for a loss-of-function mutation (Dnmtn) in the DNA methyltransferase gene. These mutant embryos failed to develop past the 25-somite stage and showed evidence of developmental delay and some developmental asynchrony. Normal embryonic and extraembryonic tissues contained similar levels of DNA methyltransferase, even though severely reduced methylation levels and a loss of imprinting have previously been observed in extraembryonic tissues. These findings suggest that methylation patterns are not a simple function of the concentration of DNA methyltransferase, and that unidentified factors must be involved in the regulation of de novo methylation during early development of the mouse.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1058-8388
pubmed:author
pubmed:issnType
Print
pubmed:volume
206
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
239-47
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8896980-5-Methylcytosine, pubmed-meshheading:8896980-Animals, pubmed-meshheading:8896980-Cell Nucleus, pubmed-meshheading:8896980-Cytoplasm, pubmed-meshheading:8896980-Cytosine, pubmed-meshheading:8896980-DNA (Cytosine-5-)-Methyltransferase, pubmed-meshheading:8896980-Decidua, pubmed-meshheading:8896980-Embryo Implantation, pubmed-meshheading:8896980-Female, pubmed-meshheading:8896980-Fetal Proteins, pubmed-meshheading:8896980-Fluorescent Antibody Technique, Indirect, pubmed-meshheading:8896980-Gene Expression Regulation, Developmental, pubmed-meshheading:8896980-Gestational Age, pubmed-meshheading:8896980-Methylation, pubmed-meshheading:8896980-Mice, pubmed-meshheading:8896980-Mice, Mutant Strains, pubmed-meshheading:8896980-Nerve Tissue Proteins, pubmed-meshheading:8896980-Nervous System
pubmed:year
1996
pubmed:articleTitle
DNA methyltransferase in normal and Dnmtn/Dnmtn mouse embryos.
pubmed:affiliation
Department of Pediatrics, McGill University, Montreal, Quebec, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't