Mitochondrial Genome Diversity across the Subphylum Saccharomycotina

Area of Science:

• * Mitochondrial genomics and evolutionary biology.
• * Comparative genomics of eukaryotic organellar DNA.

Background:

• * Eukaryotic life relies on nuclear and mitochondrial genomes, with mitochondrial genome variation influencing phenotypes and evolution.
• * Limited mitochondrial genome data exists for many yeast clades within Saccharomycotina, despite abundant nuclear genome data.

Approach:

• * Extracted and assembled mitochondrial genomes from existing short-read sequencing datasets.
• * Compared 353 yeast mitochondrial genomes to analyze size, GC content, gene presence/absence, and evolutionary rates.

Key Points:

• * Yeast mitochondrial genome size and GC content are generally consistent, with exceptions in *Metschnikowia* and *Saccharomyces* genera.
• * Loss of Complex I genes occurred in the ancestor of Saccharomycetales and Saccharomycodales, with independent losses elsewhere.
• * Mitochondrial introns are widespread, with some evidence of horizontal gene transfer.

Conclusions:

• * Expanded sampling reveals significant mitochondrial genome diversity across Saccharomycotina yeasts.
• * Mitochondrial genome evolution is complex, involving gene loss and intron dynamics.
• * Methods for retrieving mitochondrial genomes from nuclear datasets are crucial for future fungal genomics research.