Fig. 4

Genome-wide screen for alleles contributing to hybrid growth. a, b Screen for S. cerevisiae alleles contributing to hybrid growth. A hemizygote hybrid library was constructed by mating S. paradoxus with a library of S. cerevisiae strains, each of which was a deletion of one S. cerevisiae gene. Each strain was labeled by a specific barcode, enabling the measurements of relative strain abundances within a co-growing pool using sequencing. c Change in abundance of individual hemizygote strains. A pool of hybrid hemizygotes was grown in YPD + 8% ethanol. Shown are the (log) normalized barcode reads of 100 strains showing the most pronounced increase or decrease in frequency, together with 200 control strains that maintained their abundance throughout the experiment. The Z-score of the calculated growth rate for each strain is shown in the sidebar. d Growth curves of hemizygote hybrid and S. cerevisiae pools. The two hemizygote pools were kept for approximately 30 generations in the logarithmic phase through subsequent dilution, and sampled every three generations. Two independent biological replicates are shown. e Correlation between growth rates of hemizygote strains. Note the reproducibility between the two independent repeats, contrasting the low-correlation when comparing different conditions or backgrounds. f Hybrid-specific dosage sensitivity. Shown are z-scores of growth rates of strains hemizygous for genes coding for ribosomal proteins and mRNA metabolism, as indicated, that show reproducible effects in at least one condition (Z Score < –1.5; see Additional file 11: Table S5 for gene list). Missing values are shown in black. Sidebar marks previously defined haploinsufficient genes [34]