Fig. 2: H3R2 methylation is indispensable for chromosome condensation.

a–c HeLa cells were treated with siControl, siPRMT6, or siAurora B siRNA and subjected to time-lapse imaging via tomographic microscopy to assess mitotic chromosomes. The images show the three-dimensional mitotic cells right before anaphase onset. The density of metaphase chromosomes was obtained from the volume and mass calculated through the refraction rate obtained with tomographic microscopy (n = 22 chromosomes for siControl and n = 10 chromosomes for siPRMT6-A in b, n = 21 chromosomes for siControl and siAurora B in (c)). d, e Twenty-eight hours after transfection of Flag-histone H3 WT or S10A mutant, the metaphase plate width (d, n = 36 cells from three independent experiments) and inter-KT distances in Flag-positive prometaphase cells (e, n = 100 kinetochore pairs from three independent experiments) were quantified and plotted. f Following siRNA treatment, the inter-KT distances were determined in prometaphase and metaphase cells (n = 100 kinetochore pairs from three independent experiments). The insets show single focal planes of the boxed regions. g HeLa/GFP-CenpA cells were treated with siPRMT6 and subjected to time-lapse imaging with confocal microscopy for GFP-CenpA starting at 72 h after siRNA transfection. The distance between paired kinetochores was determined for control and PRMT6-depleted cells from three independent experiments (n = 10 kinetochore pairs). Scale bar, 5 μm. Error bars, SEMs. Source data are provided as a Source Data file. (Student’s t-test *p < 0.01).