Deletion of dnm1(a mitochondrial division gene) affects mitosis and energy metabolism in Schizosaccharomyces pombe

In Schizosaccharomyces pombe, the mitochondrial dynamin-related protein Dnm1 regulates dynamic mitochondrial fission/fusion． To examine the effect of dnm1 gene deletion on mitosis and energy metabolism in the fission yeast, live cells were imaged to analyze cell mitosis kinetics, RT-qPCR was performed to analyze transcription level of cdc2 and cdc13, high performance liquid chromatography-mass spectrometry was done to measure energy metabolites． The deletion of dnm1 gene led to slowed growth of fission yeast, microtubule bundles in dnm1Δ strain increased by (0.83 ± 0.70) μm (P < 0.01) when compared to the wild-type in interphase, the number of strains producing 5 microtubule bundles increased, but the number of strains producing 3 microtubule bundles decreased． The spindle elongation time in dnm1Δ prolonged by (0.85 ± 0.02) min (P < 0.05) in prophase, by (5.80 ± 1.62) min (P<0.01) in anaphase． Spindle elongation slowed down by 0.06 μm·min⁻¹ (P < 0.05) in anaphase. The dnm1Δ strain exhibited delayed spindle breakage and chromosome segregation． High-performance liquid chromatography-mass spectrometry revealed that dnm1Δ strain was deficient in coenzyme synthesis, resulting in a significant decrease in NADPH content (P < 0.05)． The relative content of intermediate metabolites (glucose 6-phosphate, fructose 6-phosphate, citric acid, cis aconitic acid, pyruvate, isocitrate, and L-malic acid) were significantly reduced (P < 0.05), with major defect in ATP production． The cdc2 gene expression in logarithmic growth phase in dnm1Δ strain was significantly lower than the wild-type．