Related species of fission yeasts feature markedly different modes of mitotic division. In the widely used cell cycle model Schizosaccharomyces pombe, the nuclear membrane does not break down during nuclear division (closed mitosis) and successful completion of mitosis is dependent upon expansion of the nuclear membrane. Blocking the synthesis of new membrane phospholipids results in catastrophic mitosis and cell death in this species. By contrast, in Schizosaccharomyces japonicus the nuclear membrane becomes partially disrupted during anaphase, and membrane expansion is not critical. We have identified Cbf11 as a transcriptional regulator of lipid synthesis that is important for successful mitosis in S. pombe. Cells lacking Cbf11 often undergo catastrophic mitosis. The aim of the project is to construct a cbf11 gene deletion knock-out in S. japonicus, analyze cell-cycle progression in the mutant, and determine whether and how the function of the Cbf11 regulatory module has been rewired in the mitosis of S. japonicus.
