Chromosome loss in tub1-729 cells overexpressing BUB3

All strains are tub1Δ, tub3Δ, SUP11-CEN-URA3, ade2-101 plus the following plasmidsFrequency of mini-chromosome loss (×10−2)
ptub1-729-LEU2-CEN pLYS2-CEN3.8
ptub1-729-LEU2-CEN pBUB3-LYS2-CEN1.9
ptub1-729-LEU2-CEN pBUB3-LYS2-2μ0.7
  • Tub1-729 cells containing the ade2-101 mutations and a mini-chromosome expressing SUP11 were transformed with an empty vector control, a high- or low-copy plasmid expressing BUB3, or a plasmid expressing wild-type TUB1. The frequency of mini-chromosome loss was determined using the method described by Christianson et al. (1992; see materials and methods). Tub1-729 cells have a higher rate of chromosome loss than wild-type cells. This enhanced rate of chromosome loss is suppressed by increasing levels of BUB3.