Simultaneous In Situ Detection of m⁶A-Modified and Unmodified RNAs Using DART-FISH

Area of Science:

• Molecular Biology
• Epigenetics
• RNA Biology

Background:

• N6-methyladenosine (m6A) is a prevalent mRNA modification crucial for RNA regulation and gene expression.
• Existing visualization methods cannot differentiate between m6A-modified and unmodified transcripts, hindering cellular localization studies.
• Understanding m6A distribution is vital for deciphering its functional roles in gene regulation.

Purpose of the Study:

• To introduce a novel technique, DART-FISH, for simultaneous visualization of m6A-modified and unmodified target mRNAs.
• To enable the investigation of m6A stoichiometry and the intracellular localization of methylated mRNAs.
• To overcome the limitations of traditional mRNA visualization methods.

Main Methods:

• DART-FISH combines m6A-dependent C-to-U editing with mutation-selective fluorescence in situ hybridization (FISH).
• This approach allows for the specific detection of both methylated and unmethylated mRNA copies.
• The technique is designed for single-cell analysis.

Main Results:

• Successful simultaneous detection of m6A-modified and unmodified target transcripts.
• Demonstration of DART-FISH's capability to analyze m6A stoichiometry.
• Visualization of methylated mRNA localization within single cells.

Conclusions:

• DART-FISH provides a powerful tool for studying m6A RNA biology at the single-cell level.
• The technique enhances our understanding of m6A modification's role in RNA function and gene expression.
• DART-FISH opens new avenues for investigating the spatial distribution and quantitative aspects of mRNA methylation.