We sequenced these two genomes to determine which parent (Sk or Sp) contributed which components of the genome using single nucleotide polymorphisms (SNPs) to distinguish them. Both strains have the Sk karyotype. The black/grey indicates DNA that is located on chromosome 1 in Sp, blue indicates DNA that is located on chromosome 2 in Sp and red indicates DNA that is located on chromosome 3 in Sp. (A) Strain KRK has only Sk alleles on chromosomes 1 and 3. Chromosome 2 in this strain was generated by a crossover between Sk and Sp between SNPs 2,113,023 and 2,115,195 (which flank the mat1 locus). (B) Strain KKR has only Sk alleles on chromosome 1. On chromosome 2 only the left-most tip has Sp alleles. This chromosome was generated by a recombination event between Sk chromosome 2 and Sp chromosome 3. The crossover occurred between SNPs at positions 2,290,808 and 2,292,393 on Sp chromosome 3. Chromosome 3 in this strain was generated by a recombination event between Sk chromosome 3 and Sp chromosome 3 that occurred between SNPs located at positions 1,558,635 and 1,559,674 on Sp chromosome 3.