368 CELL HEREDITY 



of crossing over and haploidization in the same lineage. All of the hap- 

 loids carried, in unrecombined form, the chromosome with the y marker 

 and were, therefore, su^ riho^ an^ pro paha hi'*^. A^ a consequence, 



TABLE 12.1 

 Somatic Segregants from an Aspergillus Diploid of Constitution 



so-od.,Q ribo an + + + ad^o hi 

 = o 



+ + + pro paha y ot/gg + 



(After Pontecorvo, 1958, Trends in Modem Genetics, 

 New York: Columbia University Press) 



Selection for Yellow Segregants (y or y/y) 

 Haploids Diploids 



+ + + pro paba y su ribo an + + y adon + 



126 ^ 35 



+ + + pro paha y adoQ + 



Total 126 



su ribo an + paba y ad2o + 



110 



+ + pro paba y o^jo + 



Total 154 



Selection for Adenine- Independent Segregants {su or su/su) 

 ribo an + + + su ribo an + + + ad.yn bi 



, on ^1^^ eg 



Total ~80 ^ + + pro paba y ad^^ + 



21 



su ribo an pro paba y ad 20 + 



Total 261 



Genetic Map of Chromosome 1 with Distances Expressed as Fractions 

 of 100 when Total Length of each Arm is Set at that Number 



Mitotic 23 8 69 6 72 22 



su ribo an pro paba 



Meiotic 45 23 32 41 20 39 



