APPENDIX 4 Genetics

Abstract

Part A: Genetic Nomenclature
GUIDELINES
Guidelines for C. elegans nomenclature have been published elsewhere (Horvitz et al. 1979); a brief account of the main conventions follows.

Gene Names
Genes are given names consisting of three italicized letters, a hyphen, and an arabic number, e.g., dpy-5 or let-37. These gene names refer to the mutant phenotype originally detected and/or most easily scored: dumpy in the case of dpy-5, and lethal in the case of let-37. The gene name may be followed by an italicized Roman numeral, to indicate the linkage group on which the gene maps, e.g., dpy-5 I or let-37 X.

Mutation Names
Every mutation has a unique designation. Mutations are given names consisting of one or two italicized letters followed by an italicized Arabic number, e.g., e61 or mn138. The letter prefix refers to the laboratory of isolation (listed below), as registered with the Caenorhabditis Genetics Center (CGC). Mutations known to be chromosomal rearrangements, rather than intragenic lesions, are named somewhat differently.

When gene and mutation names are used together, the mutation name is included in parentheses after the gene name, e.g., dpy-5(e61), let-37(mn138). When unambiguous (e.g., if only one mutation is known for a given gene), gene names are used in preference to mutation names (let-37 rather than mn138).

Suffixes indicating characteristics of a mutation can follow a mutation name: These are usually two-letter nonitalicized letters, e.g., e61sd, where sd stands for semidominant.

The wild-type allele of a gene is defined as that present in the Bristol N2...