GENE CONVERSION 26-20 



Table 26-10 (Continued) 



(4) 587 X 128 (Table 19-2) 



(ag me me) x (a g me MA) 

 g g g g 2 me me me me 2 MA KA MA ma 1 



MA MA ma ma 1 



b. Galactose maintained throughout cycle 



(1) 4 (Fig. 18-1) X 128 (Table 19-2) (128 ..as grown on g.ucose) 



( a G me MA) x (a g me MA.) 

 GGgg20 GGGGl 



GGGg3 Gg--1 



GGg-3 Ggegl 



(2) CIA x 15 (Fig. 18-1) (15 vias gro;vn on glucose) 



(a G ME) X (a p, me) 

 G G G g 1 ME K£ me me 1 



c. Melibiose maintained throughout cycle 



(L5B was grown (1) L5B (Table 20-2) x 20 (Tnt le 20-2) 



on glucose 



(a G me MA) X (aG ME) 



ME ME me me 4 



ME me me - 2 



d. Maltose maintained throughout cycle 



(587 was grown (l) 587 x 128 (Ta: le 19-2) 



on glucose , , , „,v 



(ag mt ma) x (a f" me MA) 



MA MA MA MA 1 

 MA MA ma ma 3 

 ma ma ms - 1 



GENETICAL ANALYSIS OF THE FOUR HAPLOPHASES FROM 

 A TRANSFORMED TRIPLY HETEROZYGOUS ASCUS 



Table 26-5 shows an ascus (1208-1209-1210-1211) in which all 

 four haplophases fermented galactose, melibiose and maltose al- 

 though one parent was a nonfermenter of all three sugars. This 

 ascus was produced by a mating between two haplophases from an 

 ascus in which regular segregation for all three alleles occurred. 

 It was subjected to genetical analysis and the following tabulation 

 on page 26-21 shows the result of backcrossing the four clones 

 from one ascus with both the nonfermenters and fermenters. 



The backcross G x g produced a total of 64 G's and 19 g's. 

 Cultures 1208, 1209, 1210, and 1211 were not only fermenters of 

 galactose but were able to transform the nonfermenters into fer- 

 menters, but the backcross to 1210 (Gx g) behaved like simple 



