Estimation of Telomeric Repeat-containing RNA from DNA/RNA Hybrid Complexes

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Telomeric repeat-containing RNA (TERRA) are long non-coding RNAs transcribed from telomeres.
• Only a subset of TERRA molecules forms stable DNA/RNA hybrids at telomeres.
• Identifying and purifying these DNA/RNA hybrids is crucial for understanding telomere biology.

Purpose of the Study:

• To outline a detailed molecular protocol for the identification and purification of in vivo formed DNA/RNA hybrids.
• To provide a streamlined and efficient method for isolating RNA attached to DNA.
• To enable the detection of all DNA/RNA hybrid regions within telomeres.

Main Methods:

• Utilized guanidine isothiocyanate for cell lysis and homogenization, preserving nucleic acid integrity.
• Employed phenol-chloroform extraction and centrifugation for phase separation, isolating RNA and DNA/RNA hybrids.
• Incorporated Proteinase K and DNase treatments to remove proteins and free RNA, respectively, followed by purification steps.

Main Results:

• Developed a streamlined protocol for direct extraction of in vivo DNA/RNA hybrid interactions.
• The method efficiently isolates RNA hybridized to DNA, enhancing reliability and reproducibility of downstream sequencing.
• Successfully recovered DNA/RNA hybrids from the interphase layer after phase separation.

Conclusions:

• The presented protocol is highly efficient for isolating RNA attached to DNA, specifically DNA/RNA hybrids at telomeres.
• This technique allows for the detection of all DNA/RNA hybrid regions, offering insights into their biological significance.
• The streamlined method minimizes procedural steps, making it a valuable tool for telomere research.