518 APPENDIX 



inbred strains of mice. 903 This list, with minor variations, was sent by Drs. Snell 

 and T. C. Carter to geneticists in 1951, asking for a vote on two alternative systems of 

 notation. That giving maximum uniformity was adopted, and dba became DBA, 

 BalbC became BALB/c, and so on. Workers were also asked to select abbreviations 

 of their own names for use in designating substrains. From the point of view of this 

 reviewer, this was the beginning of real standardization in the whole field. Most 

 instances of nonstandard usage are the result of unawareness or confusion regarding 

 the rules. 



The Committee on Standardized Nomenclature for Inbred Strains of Mice, as an 

 informal working group came to be known, was responsible for issuing the first standard- 

 ized nomenclature list in Cancer Research in 1952. 219 This paper contained the recom- 

 mended rules for symbols, a list of known inbred strains with their histories and charac- 

 teristics, and a list of users of mice with abbreviations for their names or institutions. 



As time went on, more substrains of existing strains were developed, by spontaneous 

 mutations, manipulation, or merely physical separation. New mutations and linkages 

 were discovered, strains became more widely distributed, and the list of workers grew 

 enormously. Gradually it became apparent that a reappraisal of the nomenclature 

 rules was in order. 



Following the suggestion of Dr. Hans Griineberg, the old committee on nomen- 

 clature was reactivated, reconstituted, and renamed. During the Tenth International 

 Genetics Congress in Montreal in 1958, 5 of the 7 members of the new group met, 

 were named the Committee on Standardized Genetic Nomenclature for Mice, and 

 discussed both strain and gene symbols. This present body supersedes and represents 

 an amalgamation of the older Mouse Genetics Nomenclature Committee (genes) 

 and the Committee on Standardized Nomenclature for Inbred Strains of Mice (strains). 



This body approved the revision every four years of the alphabetic list of inbred 

 strains which had appeared in Cancer Research in 1952. Discussion at the Montreal 

 meeting, at a similar one in Bar Harbor a week later, and extensive correspondence 

 among committee members, resulted in a reissue of rules for nomenclature. These 

 are unchanged in their essentials from the listing in 1952 but are somewhat more 

 specific and detailed on certain points such as substrain symbols for stocks of complex 

 origin. The rules as they now stand are given below. 



RECOMMENDED RULES FOR SYMBOLS 



1 . Definition of inbred strain. — A strain shall be regarded as inbred when it has 

 been mated brother x sister (hereafter called b x s) for twenty or more consecutive 

 generations. Parent x offspring matings may be substituted for b x s matings, 

 provided that in the case of consecutive parent x offspring matings the mating in each 

 case is to the younger of the two parents. 



2. Symbols for inbred strains. — Inbred strains shall be designated by a capital letter 

 or letters in Roman type. It is urged that anyone naming a new stock consult 



