Copy number distribution for the CHO DXB11 genome. A) Distribution of the sequencing depth of the 20661 genes in the CHO DXB11 genome. District peaks are seen at depth of 0x, 16x, 33x and 49x corresponding to a copy number in the genome of 0, 1, 2 and 3 copies. B) Sequencing depth of the scaffold carrying dhfr. The entire 0.7 Mb scaffold is seen to be present in two copies in CHO-K1 ATCC, one copy in CHO DXB11 and roughly half the scaffold was deleted completely in CHO DG44. A peak in mRNA levels indicates that dhfr is seen to be transcriptionally active in F435 from the one allele that still contains the gene. C) The ratio of GC → AT and AT → GC mutations in CHO cell lines versus the C. griseus genome. A significant bias towards GC point mutations are observed in the two CHO DXB11 cell lines compared to the four CHO-K1 cell lines. Statistical significance level: ***p < 0.001.