Figure 1.

The Jean-Talon strain is a tetraploid with reduced spore viability. (A) DNA staining and fluorescence measured for 90 colonies of the Jean-Talon strain shows peaks around the expected ploidy of 4n. (B) SNP frequency distribution in the Jean-Talon genome mapped to S. cerevisiae S288C. (C) Boxplots and numbers of viable spores per tetrad found in three biological replicates of sporulated cultures. Pictures of the spore dissection plates for the corresponding replicates are shown above. (D) Copy number profile up to 8n of the Jean-Talon genome in 250 bp windows. Black windows correspond to the expected ploidy 4n, orange windows correspond to copy number gains and blue windows to copy number losses. Long stretches of copy number gains and losses correspond to ploidy of 5n and 3n, respectively. Code to generate the figures is in File S1.