DNA Methylation at Promoter Regions Regulates the Timing of Gene Activation in Xenopus laevis Embryos

Autor: Irina Stancheva, Osman El-Maarri, Richard R. Meehan, Joern Walter, Alain Niveleau
Rok vydání: 2002
Předmět:
DNA (Cytosine-5-)-Methyltransferase 1
Transcriptional Activation
Embryo
Nonmammalian
animal structures
Xenopus
Xenopus Proteins
Midblastula
Proto-Oncogene Proteins c-myc
Xbra
Xenopus laevis
03 medical and health sciences
0302 clinical medicine
Epigenetics of physical exercise
Transcription Factor TFIIIA
Animals
DNA (Cytosine-5-)-Methyltransferases
Promoter Regions
Genetic
development
Molecular Biology
xDnmt1
030304 developmental biology
Regulation of gene expression
0303 health sciences
biology
demethylation
Gene Expression Regulation
Developmental
Promoter
Methylation
Cell Biology
DNA Methylation
biology.organism_classification
Molecular biology
DNA-Binding Proteins
embryonic structures
DNA methylation
T-Box Domain Proteins
030217 neurology & neurosurgery
Transcription Factors
Developmental Biology
Zdroj: Developmental Biology. 243(1):155-165
ISSN: 0012-1606
DOI: 10.1006/dbio.2001.0560
Popis: The levels of genomic DNA methylation in vertebrate species display a wide range of developmental dynamics. Here, we show that in contrast to mice, the paternal genome of the amphibian, Xenopus laevis, is not subjected to active demethylation of 5-methyl cytosine immediately after fertilization. High levels of methylation in the DNA of both oocyte and sperm are maintained in the early embryo but progressively decline during the cleavage stages. As a result, the Xenopus genome has its lowest methylation content at the midblastula transition (MBT) and during subsequent gastrulation. Between blastula and gastrula stages, we detect a loss of methylation at individual Xenopus gene promoters (TFIIIA, Xbra, and c-Myc II) that are activated at MBT. No changes are observed in the methylation patterns of repeated sequences, genes that are inactive at MBT, or in the coding regions of individual genes. In embryos that are depleted of the maintenance methyltransferase enzyme (xDnmt1), these developmentally programmed changes in promoter methylation are disrupted, which may account for the altered patterns of gene expression that occur in these embryos. Our results suggest that DNA methylation has a role in regulating the timing of gene activation at MBT in Xenopus laevis embryos.
Databáze: OpenAIRE
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