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Updated: Jun 13, 2025
Selective Capture of 5-hydroxymethylcytosine from Genomic DNA
Published on: October 5, 2012
Crosstalk between 6-methyladenine and 4-methylcytosine in Geobacter sulfurreducens exposed to extremely low-frequency
Zhenhua Shi1, Yingrong Zhang1, Wanqiu Chen1
1College of Resources and Environment, Fujian Agriculture and Forestry University, 15 Shang Xia Dian Road, Cang Shan District, Fuzhou, Fujian 350002, China.
Abstract:
4-Methylcytosine (4mC) and 6-methyladenine (6mA) are the most prevalent types of DNA modifications in prokaryotes. However, whether there is crosstalk between 4mC and 6mA remain unknown. Here, methylomes and transcriptomes of Geobacter sulfurreducens exposed to different intensities of extremely low frequency electromagnetic fields (ELF-EMF) were investigated. Results showed that the second adenine of all the 5'-GTACAG-3' motif was modified to 6mA (M-6mA). For the other 6mA (O-6mA), the variation in their distance from the neighboring M-6mA increased with the intensity of ELF-EMF. Moreover, cytosine adjacent to O-6mA has a much higher probability of being modified to 4mC than cytosine adjacent to M-6mA, and the closer an unmodified cytosine is to 4mC, the higher the probability that the cytosine will be modified to 4mC. Furthermore, there was no significant correlation between DNA methylation and gene expression regulation. These results suggest a reference signal that goes from M-6mA to O-6mA to 4mC.
Insights
This study reveals a novel signaling pathway in Geobacter sulfurreducens, demonstrating crosstalk between DNA modifications 6-methyladenine (6mA) and 4-methylcytosine (4mC) under electromagnetic field exposure. The findings suggest a sequential modification process influenced by field intensity.
Area of Science:
- Epigenetics
- Microbial Genomics
- Molecular Biology
Background:
- 4-Methylcytosine (4mC) and 6-methyladenine (6mA) are key DNA modifications in prokaryotes.
- The potential crosstalk and regulatory interplay between 4mC and 6mA remain largely unexplored.
- Understanding these modifications is crucial for deciphering microbial gene regulation.
Purpose of the Study:
- To investigate the relationship between 4mC and 6mA modifications in Geobacter sulfurreducens.
- To determine the impact of extremely low frequency electromagnetic fields (ELF-EMF) on DNA methylation patterns.
- To explore potential crosstalk and signaling pathways between 4mC and 6mA.
Main Methods:
- Comparative analysis of methylomes and transcriptomes from Geobacter sulfurreducens.
- Exposure of bacterial cultures to varying intensities of ELF-EMF.
- Bioinformatic analysis to identify and quantify DNA modifications (4mC and 6mA) and their genomic context.
Main Results:
- Identified a specific 6mA modification (M-6mA) at the 5'-GTACAG-3' motif.
- Observed that the distance of other 6mA modifications (O-6mA) from M-6mA varied with ELF-EMF intensity.
- Found a higher probability of 4mC formation adjacent to O-6mA compared to M-6mA, suggesting a directional modification process.
- No significant correlation was found between DNA methylation levels and gene expression.
Conclusions:
- A potential signaling pathway from M-6mA to O-6mA to 4mC is proposed.
- ELF-EMF exposure influences the spatial distribution of 6mA modifications.
- The study provides novel insights into the complex interplay of DNA modifications in prokaryotes and their response to environmental stimuli.
