SHORTER ARTICLES AND DISCUSSION 



A CROSS INVOLVING FOUR PAIRS OF MENDELIAN 

 CHARACTERS IN MICE 



The present experiment was planned as a control upon more 

 detailed work being carried on at the Bussey Institution. It 

 has, however, a distinct value, as demonstrating from a single 

 cross the existence of four independent pairs of Mendelian char- 

 acters in the color inheritance of mice. 



That the yellow and agouti factors are not inherited inde- 

 pendently of each other has been demonstrated by Sturtevant. 1 



The four pairs of characters under consideration here were 

 recorded by Castle and Little 2 and are briefly as follows: 



A = agouti, a = non-agouti. 



B = black, b = no black (brown). 



D = density, d = diluteness. 



P = dark eye, p = pink eye. 

 In each case the character represented by the small letter is 

 recessive in combination with its allelomorph, designated by a 

 large letter. 



To obtain all possible combinations of these four pairs of char- 

 acters, a single pure wild gray mouse was mated with several 

 pink-eyed dilute brown females from a homozygous stock bred 

 at the Bussey Institution and shortly to be reported upon by one 

 of the writers. 



Wild gray mice possess the dominant members of all four 

 paired characters mentioned above, and consequently have the 

 gametic formula ABDP. The pink-eyed dilute brown mouse, on 

 the other hand, exhibits the recessive conditions of the same fac- 

 tors and is of the formula abdp. It is in appearance a very 

 pale lilac color and in Miss Durham's classification is described 

 as "Silver Champagne." 3 



The F x individuals resulting from this cross (wild J 1 X pink- 

 eyed dilute brown $) were all. as expected, similar to the wild 



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