Cells culture

S. pombe strains used in this work are listed in Table 2. Cells were grown on suitable agar plates at 25 °C. Zygotes were obtained from cells of opposite mating types (h+ and h−). Half-toothpick of h+ and half- toothpick of h−were suspended in 100 ml of Edinburgh Minimal Medium minus Nitrogen (EMM-N) and spotted on to Malt Extract Agar (MEA) plates. The plates were then incubated overnight, 12–16 hours, at 25 ± 0.5 °C. For imaging, a loop full of cells from the MEA plate was resuspended in 100 ml of EMM-N. The resuspended cells were transferred to a lectin-coated (L2380, Sigma-Aldrich, St Louis, MO, USA), 35 mm (No1.5) glass bottom culture dish (MatTek Corporation, Ashland, MA, USA) and allowed to stick to the glass for 5–10 minutes. Free cells were removed by washing with EMM-N and the petri dish was filled with 2 ml of EMM-N.