APPENDIX I Genetic Nomenclature

Abstract

A recommendation for the nomenclature used in yeast genetics was published as the November 1969 supplement to Microbial Genetics. This recommendation has been followed except for a few minor changes and the designation of the mating-type genes. The following are the updated and expanded rules of nomenclature:Gene symbols are designated by three italicized letters, which should be consistent with the proposal of Demerec et al. (1966) whenever applicable, e.g., ARG. The genetic locus is identified by a number immediately following the gene symbol, e.g., ARG2. Alleles are designated by a number separated from the locus number by a hyphen, e.g., arg2–6. Although locus numbers must be consistent with the original assignment, allele numbers may be particular to each laboratory.

Gene clusters, complementation groups within a gene, or domains within a gene having different properties can be designated by capital letters following the locus number, e.g., his4A, his4B, etc.

Dominant and recessive genes are denoted by uppercase and lowercase letters, respectively, e.g., SUP6 and arg2.

When there is no confusion, wild-type genes are designated simply as +; the + may follow the locus number to designate a specific wild-type gene, e.g., sup6+ and ARG2+. Some publications prefer to use a superscript +, e.g., ARG2⁺.

Although superscripts should be avoided, it is sometimes expedient to distinguish genes conferring resistance and sensitivity by superscript R and S, respectively. For example, the genes controlling resistance to canavanine sulfate (can1) and copper sulfate (CUP1) and their sensitive alleles...