The S. pombe mitochondrial transcriptome.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Mitochondrial gene expression relies on post-transcriptional processes like RNA processing, modification, and decay.
• Defects in mitochondrial gene expression are linked to oxidative phosphorylation deficiency and human diseases.

Purpose of the Study:

• To investigate mitochondrial transcription and RNA processing in the fission yeast *Schizosaccharomyces pombe* using RNA-seq.
• To identify novel mitochondrial transcripts and RNA processing events.

Main Methods:

• RNA sequencing (RNA-seq) of mitochondrial RNAs (mt-RNAs) from *Schizosaccharomyces pombe*.
• Analysis of RNA-seq data to identify processing sites, novel transcripts, and the impact of gene inactivation.

Main Results:

• RNA-seq revealed significant variation in mt-RNA abundance and identified unusual processing by RNase P.
• Discovered previously unknown transcripts, including *rnpB*-derived fragments, mitochondrial small RNAs (mitosRNAs), mt-tRNA-derived fragments (mt-tRFs), and mt-tRNA halves.
• Inactivation of the *trz2* gene impaired mt-tRNA 3'-end processing and inhibited mt-mRNA 5'-end processing, leading to unprocessed transcript accumulation.

Conclusions:

• RNA-seq is a feasible method for studying mitochondrial RNA processing in *S. pombe*.
• The study uncovers the complexity of the fungal mitochondrial transcriptome.
• Provides a framework for future research on mitochondrial gene expression using *S. pombe* as a model.