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Updated: Aug 11, 2026
08:38
Targeted DNA Methylation Analysis by Next-generation Sequencing
Published on: February 24, 2015
Sp1 elements protect a CpG island from de novo methylation
M Brandeis1, D Frank, I Keshet
1Department of Cellular Biochemistry, Hebrew University Medical School, Jerusalem, Israel.
Nature
|September 29, 1994
Summary
Sp1 elements protect CpG islands in housekeeping genes from de novo methylation during early embryogenesis. This ensures correct genome methylation patterns essential for regulating gene expression in animals.
Area of Science:
- Epigenetics
- Developmental Biology
- Genomics
Background:
- Animal somatic cell DNA exhibits bimodal methylation: tissue-specific genes are methylated, while housekeeping genes possess unmethylated 5' CpG islands.
- Gametical methylation is erased in early embryos, necessitating re-establishment of methylation patterns each generation via de novo methylation at implantation.
Purpose of the Study:
- To investigate the role of Sp1 elements in protecting CpG islands from de novo methylation during embryogenesis.
- To elucidate the mechanism by which correct genome methylation patterns are established for basal gene regulation.
Main Methods:
- Utilizing transfection into embryonic stem cells.
- Employing transgenic mice as a model system to study gene methylation.
- Analyzing the adenine phosphoribosyltransferase (APRT) gene's CpG island methylation status.
Main Results:
- Sp1 elements were shown to play a crucial role in preventing de novo methylation of the APRT gene's CpG island.
- Demonstrated that Sp1 elements act as a recognition mechanism for protecting CpG islands.
Conclusions:
- Sp1 elements are critical for safeguarding CpG islands from de novo methylation in early development.
- This protective mechanism is essential for establishing the correct embryonic genome methylation pattern, influencing basal gene expression.
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