Microtubule-mitochondrial attachmentfacilitates cell division symmetry and propermitochondrial partitioning in fission yeast

Abstract

Association with microtubules inhibits the fission of mitochondria in Schizosachharomyces pombe. Here we show that this attachment of mitochondria to microtubules is an important cell intrinsic factor in determining division symmetry. By comparing mutant cells that exhibited enhanced attachment and no attachment of mitochondria to microtubules (Dnm1{Delta} and Mmb1{Delta} respectively), we show that microtubules in these mutants displayed aberrant dynamics compared to wild-type cells, which resulted in errors in nuclear positioning. This translated to cell division asymmetry in a significant proportion of both Dnm1{Delta} and Mmb1{Delta} cells. Asymmetric division in Dnm1{Delta} and Mmb1{Delta} cells resulted in unequal distribution of mitochondria, with the daughter cell that received more mitochondria growing faster than the other daughter. Taken together, we show the existence of homeostatic feedback controls between mitochondria and microtubules in fission yeast, which directly influence mitochondrial partitioning and thereby, cell growth.