Evidence for biased segregation and recombination of mitochondrial genomes during crossing and meiosis of different Schizosaccharomyces pombe strains

During meiosis, tethering of parental mitochondria to opposite cell poles inhibits mixing of mitochondria with different genomes and ensures uniparental inheritance in the standard laboratory strain of fission yeast. We here investigate mitochondrial inheritance in crosses between natural isolates using tetrad dissection and next-generation sequencing. We find that colonies grown from single spores can sometimes carry a mix of mitochondrial genotypes, that mitochondrial genomes can recombine during meiosis, and that some parental strains may promote a deviation from the expected 2:2 segregation of mitochondrial alleles. Together, these findings paint a more nuanced picture of mitochondrial inheritance in the wild.