| Autor: |
Turkington, Roger W., Spielvogel, Richard L. |
| Zdroj: |
Journal of Biological Chemistry; June 1971, Vol. 246 Issue: 12 p3835-3840, 6p |
| Abstrakt: |
The methylation of DNA in organ cultures of mouse mammary gland has been studied during hormone-dependent cell proliferation and cell differentiation. Methionine-methyl-14C was incorporated into DNA, and 5-methylcytosine was the only methylated base found. Incubation of explants with insulin and other factors induced coordinate and proportional increases in the rates of DNA replication and methylation in the epithelial cells. DNA methylation was prevented by inhibitors of DNA synthesis. Density labeling of the DNA with 5-bromo-2'-deoxyuridine demonstrated that the newly synthesized segments of DNA were methylated in these experiments. Induction of cell differentiation by insulin, hydrocortisone, and prolactin was not associated with alteration of the methylation of main or satellite DNA, and did not alter the formation of 5-methylcytosine-containing dipyrimidine sequences. These results indicate that DNA methylation has an obligatory dependence upon DNA synthesis, but is otherwise independent from the hormonal regulation of mammary cell differentiation. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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