Figure 4.

(A) The level of H3K9me3 at alpha satellite repeats and their neighboring regions after HS in the presence of chaetocin, inhibitor of histone methyltransferase Suv39H1. H3K9me3 level at intronic alpha satellite repeats No 1, 10, 14, 18, 19, 25, 21, 28, 29, 31 and at the regions positioned 2–6 kb from each of the alpha repeat, either at 5′ or 3′ site is presented in MJ90 hTERT cells. In Cal 27, OV-90, and HepG2 cells, H3K9me3 level was shown for polymorphic ARs 10 and 29. AR 29 is absent in Cal 27 and OV-90 cells (29-), while AR 10 is absent on a single allele in HepG2 cells (10-). (B) Expression of genes associated with dispersed alpha satellite repeats after HS in the presence of chaetocin. Genes associated with six intronic ARs: 1, 10, 14, 19, 25, and 29, and with eight intergenic ARs are expressed in MJ90 hTERT cells. Expression of genes ZNF675 and NR3C1 which are associated with polymorphic ARs 29 and 10, respectively, is also examined in Cal 27 (AR 29-), OV-90 (AR 29-), and HepG2 (AR 10-) cells. Cells were treated with 150 µM chaetocin during 2 h of heat stress at 42 °C. H3K9me3 level and gene expression were measured immediately after HS and compared with the controls without chaetocin. H3K9me3 was measured by ChIP-qPCR, No values were normalized using No value of input fraction and relative No values are shown which are obtained by dividing each No value by No value of control (no chaetocin). Expression of genes is shown in relative No values which are obtained by dividing each No value by No value of control (no chaetocin), for each gene. Columns show average of two different qRT-PCR experiments performed in triplicate and error bars represent standard deviations.