SPECIFICITY OF GENE EFFECTS 253 



Notwithstanding the fact tliat H, (1, and K are recognized sei)arately by- 

 respective reagents, these data, and the observation that K has occurred 

 only with both H and G, are strong evidence for tlie conclusion that B, G, and 

 K in the cells behave as a unit. 



Further, offsj)ring of some individuals ])ossessing B and G (BG) in their 

 cells have given only two classes of offspring, those with B and those with G, 

 as would be expected if the causative genes were alleles. But another type of 

 BG individual has produced offspring of two quite different types — those 

 with both B and G (BG) and those with neither, as if a gene producing B and 



TABLE 15.4 



THE DISTRIBUTION OF THE CONSTITUENTS OF 



THE "B" COMPLEXES IN THE OFFSPRING 



OF SELECTED SIRES 



G together was allelic to one not effecting either B or G. These combinations 

 of antigenic substances, as BG and BGK, have been called antigenic com- 

 plexes. 



There are two series of such complexes, called the B and C series, respec- 

 tively. In the B series there are twenty-one of the forty-odd antigenic char- 

 acters which are associated in various conbinations. At least seven of these 

 may appear singly, as was described for B and G. The other fourteen have 

 been found only in various antigenic complexes, each of which may be made 

 up of from two to eight of the twenty-one characters. The majority of these 

 twenty-one characters do not occur at random in a complex with each of the 

 others. As was stated above, the character K has always been found with B 

 and G, but it has never occurred with I, with which it appears as a contrast- 

 ing substance. In contrast, either B or G may be present in a complex with I. 

 No separation of the antigenic characters of a complex has ever been ob- 

 served in the cells of the offspring of an individual possessing it. A few ex- 

 amples are listed in Table 15.4 from more complete data given in a paper by 

 Stormont, Owen, and Irwin (1951). All present evidence makes it seem some- 

 what more reasonable to assume that each antigenic complex is produced by 

 a single gene than by linked genes. The various antigenic complexes in each 



