Fig. 1

Aneuploidy of ulp2Δ cells can be reversed by laboratory evolution. a Scheme for creation of nascent ulp2Δ cells and their subsequent passaging. The ulp2Δ cells containing YCplac33-ULP2 were streaked on SD + FOA plates twice sequentially to evict the YCplac33-ULP2 plasmid, and they were then transformed either with YCplac33-ULP2 or YCplac33. Cells grew for ~50 generations (50 G) during these procedures. For long-term passaging, cells were grown until saturation and then diluted 1:120 in fresh YPD (6.9 generations per dilution). This process was repeated daily. b Chromosome copy number of ulp2Δ cells with the indicated plasmids was monitored by qPCR assay at the indicated number of generations. Copy number was determined relative to WT (MHY500 + YCplac33) cells. Chromosome copy number between 50 and 250 generations were monitored previously¹⁸, and the data are included here. c Growth of the indicated ulp2Δ strains at 50G and 500G. After spotting cells in fivefold serial dilutions, the YPD plates were incubated for 2 days at 30 °C. d Immunoblot analysis of sumoylated proteins in extracts prepared from the strains in c. Anti-Pgk1 blotting was used to verify the equal loading. Asterisks indicate reintroduced YCplac33-ULP2. The stacking gel (bracket) and molecular size standards are indicated. e Flow cytometry of DNA content of the strains from c. 1C and 2C indicate unreplicated DNA (haploid) and replicated DNA (diploid), respectively