Figure EV1. DKO of HP1α and HP1γ causes defective mitosis progression (related to Fig 1).

• A
  EGFP‐HP1β was transiently expressed in HeLa cells in which endogenous HP1β was stably knocked out by CRISPR/Cas9. Chromosome spreads prepared from nocodazole‐arrested mitotic cells were immunostained. Scale bar, 10 μm.
• B, C
  Genomic DNA sequencing of HeLa‐derived clones in which HP1α (B), or HP1α and HP1γ (C), were knocked out. The genomic DNA PCR fragments were subcloned and sequenced. For clone 1D4 cells, all 12 bacterial colonies showed insertion of 13 bases. For clone 2A4 cells, all eight bacterial colonies showed insertion of one base. For clone 3A2 cells, all 10 bacterial colonies showed insertion of 38 bases. For clone 4A4 cells, 7 out of 12 bacterial colonies showed insertion of 22 bases, whereas the rest five bacterial colonies showed insertion of 57 bases and deletion of two bases.
• D
  Genomic DNA sequencing of HeLa‐derived clone 2A5 cells in which HP1β was knocked out. The genomic DNA PCR fragments were subcloned and sequenced. Three out of 12 bacterial colonies showed deletion of 35 bases, whereas the rest nine bacterial colonies showed insertion of 34 bases.
• E, F
  Asynchronous HeLa and the indicated HP1β KO clone 2A5 were immunoblotted (E), or were fixed and stained with ACA and DAPI. The percentage of cells with lagging chromosomes was determined in 100 anaphase cells.
• G
  The mitosis progression of HeLa and HP1 DKO clone 3A2 cells stably expressing H2B‐GFP were analyzed by time‐lapse live imaging (related to Fig 1D). The time from NEB to metaphase chromosome alignment, and from metaphase to anaphase onset, was determined (unpaired t‐test). Means and SDs are shown.

Source data are available online for this figure.