Table 1 Nineteen natural isolates that contain incompatible MLH1–PMS1 combinations
Isolate nameGenotype MLH1PMS1Ploidy (n)Origin (ecological, geographical)
CLIB324_2SK1/S288cSK1/S288c2Bakery, Vietnam
CBS4455S288cSK1/S288c3Beer, South Africa
CECT1462SK1/S288cSK1/S288c4Beer, United Kingdom
NCYC_2780SK1/S288cSK1/S288c4Human clinical, Belgium
2680SK1/S288cSK1/S288c4Human clinical, Spain
YS8(E)SK1/S288cSK1/S288c4Bakery, unknown
SD-15SK1/S288cSK1/S288c4Bakery, Italy
WLP001SK1/S288cSK1/S288c4Beer, USA
WLP013SK1/S288cSK14Beer, United Kingdom
WLP006SK1/S288cSK14Beer, unknown
UCD_06-645SK1/S288cSK1/S288c4Fruit, Davis, California
Win-8BSK1/S288cSK12Beer, United Kingdom
Ponton 11SK1/S288cSK1/S288c2Human clinical, Spain
CLI_16SK1/S288cSK1/S288c4Human clinical, France
CLI_19SK1/S288cSK1/S288c2Human clinical, France
CLI_23SK1/S288cSK1/S288c4Human clinical, France
CLI_26SK1/S288cSK1/S288c4Human clinical, France
YJM521SK1/S288cSK1/S288cNTHuman clinical, California
YJM523S288cSK1NTHuman clinical, California
  • The 1010 isolates were genotyped at amino acid 761 for MLH1 and amino acid 818 in PMS1. Isolates were genotyped as S288c if they contained the S288c amino acids (D761 in MLH1 and R818 in PMS1), and SK1 if they contained the SK1 amino acids (G761 in MLH1 and K822 in PMS1). SK1/S288c indicates that both SK1 and S288c alleles were detected in the strain at the indicated locus. We analyzed the yeast genomes of the 1010 isolates by placing them into clades. We then computed the mean, median, SD, and SE for the number of singletons within these clades and compared the number of singletons of the 19 isolates to their associated clades. We did not observe an excess of singletons for any of the isolates (1002 Yeast Genomes Project; http://1002genomes.u-strasbg.fr/). Ploidy was determined by FACS, and all but CLIB324_2, WLP001, and Win-8B are capable of sporulating (Materials and Methods). NT, not tested.