52 GENETIC STOCKS AND BREEDING METHODS 



The case in which the gene of interest is sex linked is of some interest in mice. 

 In the case in which the males are dY and the females Dd, there are six types of corre- 

 lations to consider. The gametic diagrams are shown in figure 17. In the cases 

 of two spermatozoa or two eggs, the alternative possibilities, production by the same 

 individual (probabilities l/N m , 1/N f ) and by different individuals (N m - l)/N mi 

 (N f — \)jN f are both shown. 



Fig. 17. Mating type of dY x Dd. 

 r Oo 



m \j 



c l-c cl-c c l-c 



W H V 



Do D„ Do 



d D y d s O p 



\ J / 



I l-c c 



\. 1/ 



c l-c 



V V V 



00 



d a y d DY 



A 

 1 \ 



"s X 



■ss 



ds o'/?° F ' d *6> 



/ 1 / 



I / 



l-c c l-c c l-c c 



4/ v V 



V 



'00 



'0o 



00 



Diagrams for analysis of six types of gametic pairs with respect to sex-linked locus. 



The formulae for the correlations can be written from inspection. The co- 

 efficients are listed below : 



The characteristic equation is thus a rather complicated sextic. In the case of 



