TABLE 4

Summary of effects of changes in histone gene copy number on spt16 and pob3 mutants

Change in copy numberGene ratio of
H2A-H2B/H3-H4
Effect on growth of strain with
H2A-H2BH3-H4spt16-11pob3-7
IncreaseHighWorseBetter
DecreaseHighWorseBetter
DecreaseLow(Better)Worse
IncreaseLowBetter(Worse)
  • Changes in growth upon deletion or addition of copies of histone genes are indicated as a function of the change in the ratio of H2A-H2B gene sets to H3-H4 gene sets. Representative data are shown in Figures 3 and 4, but similar results have been obtained in other strains from the A364a, W303, and S288c backgrounds (data not shown). More subtle effects are indicated by parentheses.