Nucleotide-sequence-specific de novo methylation in a somatic murine cell line.

AUTOR(ES)

Szyf, M

RESUMO

DNA fragments encoding the mouse steroid 21-hydroxylase (C21 or Cyp21A1) gene are de novo methylated when introduced into the mouse adrenocortical tumor cell line Y1 by DNA-mediated gene transfer. Although CCGG sequences within the C21 gene are de novo methylated, CCGG sites within flanking vector sequences, other mammalian gene sequences driven by the C21 promoter, and the neomycin-resistance gene, which was cotransfected with the C21 gene, do not become methylated. At least two separate signals for de novo methylation are encoded within the gene since three fragments derived from the C21 gene were methylated de novo. Specific de novo methylation of C21-derived sequences does not occur in L cells or Y1 kin8 cells; this suggests that the cellular factors needed for de novo methylation of the C21 gene are not ubiquitous. Most DNA sequences are not de novo methylated when introduced into somatic cells and DNA sequences other than the C21 gene are not de novo methylated when introduced into Y1 cells. Several groups have suggested that de novo methylation occurs in early embryonic cells and that somatic cells strictly maintain their methylation pattern by a semiconservative methyltransferase. Our results suggest that de novo methylation of specific nucleotide sequences can occur in some mammalian somatic cells.

Documentos Relacionados

• Nucleotide-sequence-specific and non-specific interactions of T4 DNA polymerase with its own mRNA
• Theiler's murine encephalomyelitis virus subgroup strain-specific infection in a murine macrophage-like cell line.
• Nucleotide sequence of an unequal sister chromatid exchange site in a mouse myeloma cell line.
• Protection against murine disseminated candidiasis mediated by a Candida albicans-specific T-cell line.
• Multiplication of Listeria monocytogenes in a murine hepatocyte cell line.