FIGURE 1:

The defect of sgo1Δ and bub1Δ strains is suppressed by BIR1 or SLI15 overexpression. (A) Overexpression of SGO1, BIR1, and SLI15 under control of their own promoter and carried on 2-μm plasmids suppresses the temperature sensitivity of bub1Δ tetraploids. Two independent clones were tested for each genotype, and cells were plated by fivefold serial dilution on plates lacking leucine (to select for plasmid retention) and containing 5-FOA (counterselection against plasmid containing the wild-type BUB1). The 2-μm LEU2 vector pRS425 (“empty”) and a LEU2-marked centromeric plasmid containing BUB1 were used as negative and positive controls, respectively. (B) Overexpression of BIR1 and SLI15 suppresses the lethality of sgo1Δ tetraploids at 37°C. The setup is identical to the previous experiment. (C) BIR1 and SLI15 overexpression suppresses the sensitivity of haploid sgo1Δ cells to the microtubule-depolymerizing drug benomyl. (D) The genetic interaction is not reciprocal, as overexpression of SGO1 does not improve the growth of sli15-3 mutants at the minimal restrictive temperature (35°C).