METHODS OF KEEPING RECORDS 



533 



descendants of sibling pairs many generations before. This type of propagation 

 encourages subline formation within an inbred strain. Pedigree charts are also essential 

 to determine relationships of deviants arising in the colony and perhaps give information 

 about the inheritance of the deviant. In production colonies such charts will show 

 the portion of the pedigree that must be eliminated from the colony (figures 77, 78, 

 and 79). 



Fig. 78. Pedigree chart of the relations of a deviant that appeared in an 



INBRED STRAIN. 



AKR/J 



8 



^ 



T n n IT — I JL I l r 



lUi . 1574 % , ZVfcX , 2378 X , (y) 05 2«f 



probably not coffin's 



162X165 1 



0© 





® 



PeJicjree for hu 

 FS 



2.524 X , 



SOK 



1 1 



Z526X , 



Such a chart shows (1) that the animals that should be removed from the main colony 

 and (2) those animals that can be eliminated because they are probably not carriers of this 

 new deviant. Outcross tests of both the female and male to known heterozygotes would 

 be needed to establish this conclusively. 



Fig. 79. Pedigree chart of the relations of a lethal deviant that appeared in the 



production colony. 



J)bts/\J 



Fdiarut for anemics 



j.liminate' 



eliminate 



Study of the chart reveals the fate of the relatives and those animals that must be 

 removed immediately from the colony. All other matings were checked and found to have 

 been discarded or not to be carriers. 



