Oligonucleotide transformation for the study of mutagenic specificities of DNA lesions in yeast
Kazuo Negishi1, Daijiro Sekine, Takumi Morimitsu
1Nihon Pharmaceutical University, 10281 Komuro, Ina, Saitama 362-0806, Japan. knegishi@nichiyaku.ac.jp
Abstract:
We developed a method for the analyzing mutagenic potential of DNA damage based on the oligonucleotide transformation technique in yeast. Using this assay we have analyzed mutagenic specificities of various DNA lesions. In the present study, we analyzed the mutagenic properties of 2-hydroxyadenine and 5-hydroxycytosine in yeast. Oligonucleotides containing 2-hydroxyadenine or 5-hydroxycytosine were used for the transformation. The oligonucleotides showed transforming activities similar to unmodified oligonucleotides. This indicates that no repair systems were working on them. The sequencing data of the transformants showed that 5-hydroxycytosine and 2-hydroxyadenine are read mainly as cytosine and adenine. We will also discuss the mechanism of oligonucleotide transformation and its application to the mutagenesis study.
Insights
This study reveals how DNA damage from 2-hydroxyadenine and 5-hydroxycytosine causes mutations in yeast. These DNA lesions are primarily misread as cytosine and adenine during genetic transformation.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- DNA damage can lead to mutations, impacting cellular function and organismal health.
- Understanding the mutagenic potential of specific DNA lesions is crucial for assessing genotoxicity.
- The oligonucleotide transformation technique in yeast provides a model system to study DNA repair and mutagenesis.
Purpose of the Study:
- To analyze the mutagenic properties of 2-hydroxyadenine and 5-hydroxycytosine using yeast transformation.
- To investigate the repair and mutagenic specificity of these oxidative DNA lesions.
- To explore the mechanism of oligonucleotide transformation in mutagenesis studies.
Main Methods:
- Development of a yeast-based oligonucleotide transformation assay.
- Synthesis of oligonucleotides containing 2-hydroxyadenine or 5-hydroxycytosine.
- Transformation of yeast with modified oligonucleotides and sequencing of resulting transformants.
Main Results:
- Oligonucleotides with 2-hydroxyadenine and 5-hydroxycytosine exhibited similar transforming activities to unmodified ones, suggesting a lack of repair.
- Sequencing data indicated that 5-hydroxycytosine was predominantly misread as cytosine.
- 2-hydroxyadenine was mainly misread as adenine during yeast transformation.
Conclusions:
- 2-hydroxyadenine and 5-hydroxycytosine are mutagenic lesions in yeast, primarily causing base substitutions.
- The yeast oligonucleotide transformation assay is effective for studying the mutagenic specificity of DNA damage.
- Further research into DNA repair mechanisms and mutagenesis is warranted.
