MICROTUBULES MEDIATE MITOCHONDRIAL DISTRIBUTION IN FISSION YEAST

The Schizosaccharomyces pombe mutant, ban5-4, displays aberrant mitoch ondrial distribution. Incubation of this conditional-lethal mutant at the nonpermissive temperature led to aggregated mitochondria that were distributed asymmetrically within the cell. Development of this mitoc hondrial asymmetry but not mitochondrial aggregation required progress ion through the cell division cycle. Genetic analysis revealed that ba n5-4 is an allele of atb2 encoding alpha 2-tubulin. Consistent with th is finding, cells with the cold-sensitive nda3 mutation in beta-tubuli n displayed aggregated and asymmetrically distributed mitochondria aft er incubation at lowered temperatures. These results indicate that mic rotubules mediate mitochondrial distribution in fission yeast and prov ide the first genetic evidence for the role of microtubules in mitocho ndrial movement.