Enetic backgrounds, S288c and SK1 (S1 Table). A equivalent but differently marked S288c/SK1 hybrid was previously utilized for meiotic tetrad analyses [19]. General, the diploid includes >62,000 single nucleotide polymorphisms (SNPs), distributed along the 16 homologous chromosomes (S1A Fig) resulting in a genome wide divergence of 0.7 [20,21]. The average inter-SNP distance is 191bp (S1B Fig).