Cytosine methylation and mammalian development.

ABSTRACT: Programmed methylation and demethylation of regulatory sequences has been proposed to play a central role in vertebrate development. We report here that the methylation status of the 5' regions of a panel of tissue-specific genes could not be correlated with expression in tissues of fetal and newborn mice. Genes reported to be regulated by reversible methylation were not expressed ectopically or precociously in Dnmt1-deficient mouse embryos under conditions where demethylation caused biallelic expression of imprinted genes and activated transcription of endogenous retroviruses of the IAP class. These and other data suggest that the numerous published expression-methylation correlations may have described not a cause but a consequence of transcriptional activation. A model is proposed under

SUBMITTER: Walsh CP 

PROVIDER: S-EPMC316374 | biostudies-literature | 1999 Jan

REPOSITORIES: biostudies-literature