Two novel lncRNAs discovered in human mitochondrial DNA using PacBio full-length transcriptome data

Area of Science:

• Mitochondrial biology
• Genomics
• RNA sequencing

Background:

• Mitochondrial RNA (mtRNA) research is crucial for understanding cellular function.
• Previous studies lacked comprehensive full-length mtRNA data.
• PacBio sequencing offers long-read capabilities for transcript analysis.

Purpose of the Study:

• To establish a framework for PacBio full-length transcriptome sequencing of mtRNAs.
• To produce the first comprehensive human mitochondrial transcriptome.
• To discover novel RNA species and refine mitochondrial genome annotations.

Main Methods:

• Utilized PacBio single-molecule, real-time (SMRT) sequencing.
• Analyzed public PacBio data for human mitochondrial transcripts.
• Developed a novel framework for mtRNA investigation.

Main Results:

• Generated the first full-length human mitochondrial transcriptome.
• Determined the H-strand primary transcript and identified novel transcripts (e.g., ND5/ND6AS/tRNA^GluAS).
• Discovered palindrome small RNAs (psRNAs) and proposed a "mitochondrial cleavage" model.
• Identified two ubiquitous novel long non-coding RNAs (lncRNAs): MDL1 and MDL1AS in animal mitochondrial genomes.

Conclusions:

• The findings fundamentally revise human mitochondrial genome annotations.
• This work significantly advances the understanding of animal mitochondrial transcriptomes.
• The discovery of MDL1 and MDL1AS lncRNAs opens new avenues in mitochondrial research.