Abstract
The herpesvirus thymidine kinase gene has been used to introduce foreign DNA sequences into mouse L cells by DNA-mediated gene transfer. These inserted genes were then assayed for methylation at the specific sequence C-C-G-G by using the restriction enzyme isoschizomers Hpa II and Msp I. Despite the fact that 70% of the cellular C-C-G-G sites are methylated, herpesvirus sequences, plasmid DNA, and growth hormone gene DNA were found to remain unmethylated in 90% of the clones that contain these genes. DNA that had been methylated in vitro with Hpa II methylase was also inserted into L cells. The presence of this modification in the vector DNA did not, however, guarantee that these sequences remained methylated in the recipient clones. Only 10% of all transformed clones were found to contain methylated C-C-G-G sequences in the vector DNA, and these modifications were stable for 25-50 generations. Hha I and Mbo I were used to probe for methyl groups at these restriction sites, but none of the inserted sequences acquired these modifications. These results are discussed in relation to various models put forth to explain the process of methylation in eukaryotic cells.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bird A. P., Taggart M. H., Smith B. A. Methylated and unmethylated DNA compartments in the sea urchin genome. Cell. 1979 Aug;17(4):889–901. doi: 10.1016/0092-8674(79)90329-5. [DOI] [PubMed] [Google Scholar]
- Bird A. P. Use of restriction enzymes to study eukaryotic DNA methylation: II. The symmetry of methylated sites supports semi-conservative copying of the methylation pattern. J Mol Biol. 1978 Jan 5;118(1):49–60. doi: 10.1016/0022-2836(78)90243-7. [DOI] [PubMed] [Google Scholar]
- Cedar H., Solage A., Glaser G., Razin A. Direct detection of methylated cytosine in DNA by use of the restriction enzyme MspI. Nucleic Acids Res. 1979;6(6):2125–2132. doi: 10.1093/nar/6.6.2125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Clewell D. B. Nature of Col E 1 plasmid replication in Escherichia coli in the presence of the chloramphenicol. J Bacteriol. 1972 May;110(2):667–676. doi: 10.1128/jb.110.2.667-676.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Desrosiers R. C., Mulder C., Fleckenstein B. Methylation of Herpesvirus saimiri DNA in lymphoid tumor cell lines. Proc Natl Acad Sci U S A. 1979 Aug;76(8):3839–3843. doi: 10.1073/pnas.76.8.3839. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harbers K., Harbers B., Spencer J. H. Nucleotide clusters in deoxyribonucleic acids. XII. The distribution of 5-methylcytosine in pyrimidine oligonucleotides of mouse L-cell satellite DNA and main band DNA. Biochem Biophys Res Commun. 1975 Sep 16;66(2):738–746. doi: 10.1016/0006-291x(75)90572-0. [DOI] [PubMed] [Google Scholar]
- Holliday R., Pugh J. E. DNA modification mechanisms and gene activity during development. Science. 1975 Jan 24;187(4173):226–232. [PubMed] [Google Scholar]
- KIT S., DUBBS D. R., PIEKARSKI L. J., HSU T. C. DELETION OF THYMIDINE KINASE ACTIVITY FROM L CELLS RESISTANT TO BROMODEOXYURIDINE. Exp Cell Res. 1963 Aug;31:297–312. doi: 10.1016/0014-4827(63)90007-7. [DOI] [PubMed] [Google Scholar]
- Mandel J. L., Chambon P. DNA methylation: organ specific variations in the methylation pattern within and around ovalbumin and other chicken genes. Nucleic Acids Res. 1979 Dec 20;7(8):2081–2103. doi: 10.1093/nar/7.8.2081. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mann M. B., Smith H. O. Specificity of Hpa II and Hae III DNA methylases. Nucleic Acids Res. 1977 Dec;4(12):4211–4221. doi: 10.1093/nar/4.12.4211. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McGhee J. D., Ginder G. D. Specific DNA methylation sites in the vicinity of the chicken beta-globin genes. Nature. 1979 Aug 2;280(5721):419–420. doi: 10.1038/280419a0. [DOI] [PubMed] [Google Scholar]
- Miller O. J., Schnedl W., Allen J., Erlanger B. F. 5-Methylcytosine localised in mammalian constitutive heterochromatin. Nature. 1974 Oct 18;251(5476):636–637. doi: 10.1038/251636a0. [DOI] [PubMed] [Google Scholar]
- Molitor H., Drahovsky D., Wacker A. Unmethylated DNA in mouse L cells. I. DNA fibre autoradiography. Biochim Biophys Acta. 1976 Apr 15;432(1):28–36. doi: 10.1016/0005-2787(76)90038-1. [DOI] [PubMed] [Google Scholar]
- Pellicer A., Wigler M., Axel R., Silverstein S. The transfer and stable integration of the HSV thymidine kinase gene into mouse cells. Cell. 1978 May;14(1):133–141. doi: 10.1016/0092-8674(78)90308-2. [DOI] [PubMed] [Google Scholar]
- Razin A., Cedar H. Distribution of 5-methylcytosine in chromatin. Proc Natl Acad Sci U S A. 1977 Jul;74(7):2725–2728. doi: 10.1073/pnas.74.7.2725. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Riggs A. D. X inactivation, differentiation, and DNA methylation. Cytogenet Cell Genet. 1975;14(1):9–25. doi: 10.1159/000130315. [DOI] [PubMed] [Google Scholar]
- SINSHEIMER R. L. The action of pancreatic deoxyribonuclease. II. Isomeric dinucleotides. J Biol Chem. 1955 Aug;215(2):579–583. [PubMed] [Google Scholar]
- Singer J., Roberts-Ems J., Riggs A. D. Methylation of mouse liver DNA studied by means of the restriction enzymes msp I and hpa II. Science. 1979 Mar 9;203(4384):1019–1021. doi: 10.1126/science.424726. [DOI] [PubMed] [Google Scholar]
- Solage A., Cedar H. Organization of 5-methylcytosine in chromosomal DNA. Biochemistry. 1978 Jul 11;17(14):2934–2938. doi: 10.1021/bi00607a036. [DOI] [PubMed] [Google Scholar]
- Sutcliffe J. G. pBR322 restriction map derived from the DNA sequence: accurate DNA size markers up to 4361 nucleotide pairs long. Nucleic Acids Res. 1978 Aug;5(8):2721–2728. doi: 10.1093/nar/5.8.2721. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sutter D., Doerfler W. Methylation of integrated adenovirus type 12 DNA sequences in transformed cells is inversely correlated with viral gene expression. Proc Natl Acad Sci U S A. 1980 Jan;77(1):253–256. doi: 10.1073/pnas.77.1.253. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weinstock R., Sweet R., Weiss M., Cedar H., Axel R. Intragenic DNA spacers interrupt the ovalbumin gene. Proc Natl Acad Sci U S A. 1978 Mar;75(3):1299–1303. doi: 10.1073/pnas.75.3.1299. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wigler M., Silverstein S., Lee L. S., Pellicer A., Cheng Y. c., Axel R. Transfer of purified herpes virus thymidine kinase gene to cultured mouse cells. Cell. 1977 May;11(1):223–232. doi: 10.1016/0092-8674(77)90333-6. [DOI] [PubMed] [Google Scholar]
- Wigler M., Sweet R., Sim G. K., Wold B., Pellicer A., Lacy E., Maniatis T., Silverstein S., Axel R. Transformation of mammalian cells with genes from procaryotes and eucaryotes. Cell. 1979 Apr;16(4):777–785. doi: 10.1016/0092-8674(79)90093-x. [DOI] [PubMed] [Google Scholar]
- van der Ploeg L. H., Flavell R. A. DNA methylation in the human gamma delta beta-globin locus in erythroid and nonerythroid tissues. Cell. 1980 Apr;19(4):947–958. doi: 10.1016/0092-8674(80)90086-0. [DOI] [PubMed] [Google Scholar]




