26-21 THE YEAST CELL 



1208 G ME MA 1209 G ME KA 1210 G ME MA 1211 G ME MA 

 Backcross to non fermenter g me ma 

 8 G, 3 g 12 G, g 11 G, 10 g 33 G, 6 g 



IGGGG 3GGGG 4GGgg 6GGGG 



2 G G G g 

 1 g g g g 



10 ME, 1 me 12 ME, me 11 ME, 10 me 21 ME, 18 me 



IMEMEMEME 3MEMEMEME iMEMEMEme 5MEMEmeme 



iMEMEMEme 3MEMEmeme 2MEMEMEME 



1 ME ME ME me 



11 MA, 1 ma 10 MA, 2 ma 19 MA, 1 ma 25 MA, 10 ma 



2MAMAMAMA IMAMAMAMA 3MAMAMAMA 4MAMAMAMA 



2 MA MA MA ma 1 MA MA MA ma 2 MA MA MA ma 



1 MA M/. ma ma 

 1 ma ma ma ma 



Backcrn.QR to fermenter G ME MA 



4 G, g 12 G, g 16 G, g 20 G, g 



IGGGG 3GGGG 4GGGG 5GGGG 



4 ME, me 12 ME, me 16 MF, me 19 ME, 1 me 



1 ME M£' ME ME 3 MF ME ME ME 4 ME ME ME ME 4 ME ME ME ME 



1 ME ME ME me 



4 MA, ma 12 MA, ma 16 MA, ma 20 MA, ma 



1 MA MA MA MA 3 MA MA MA MA 4 MA MA MA. MA 5 MA MA MA MA 



heterozygous cross with regular segregations. The backcross to 

 me produced a total of 54 ME's to 29 me's. The backcross to 1211 

 produced 5 of tiie expected ME ME me me asci; the mating with 1210 

 produced 3. Otherwise the asci all fell into unexpected categories. 

 Both 1208 and 1209 transformed the nonfermenters, with which they 

 were mated, to fermenters. The backcross to the triple recessive 

 yielded 65 fermenters of maltose to 14 nonfermenters of maltose; 

 only 1 ascus of the expected MA MA ma ma type was obtained. 

 Transformation was the rule rather than the exception with the MA/ 

 ma alleles. 



Backcrossed to the galactose fermenter, only fermenters were 

 obtained, indicating that the transformed cultures were complete 

 dominants. The backcrosses to the dominant ME yielded 1 me to 



