APPENDIX 1 Genetics

Abstract

PART A: GENETIC NOMENCLATURE
The genetic nomenclature summarized here is based on the original proposals for Caenorhabditis elegans nomenclature (Horvitz et al. 1979), plus additional recommendations that have been distributed in The Worm Breeder’s Gazette.

Genetic Loci
Genes are given names consisting of three italicized letters, a hyphen, and an arabic number, e.g., dpy-5 or let-37 or mlc-3. 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 or mlc-3 III.

For genes defined by mutation, the gene names refer to the mutant phenotype originally detected and/or most easily scored: dumpy (DumPY) in the case of dpy-5, and lethal (LEThal) in the case of let-37.

For genes defined by cloning, on the basis of sequence similarity, the gene name refers to the predicted protein product or RNA product: Myosin Light Chain in the case of mlc-3, SuperOxide Dismutase in the case of sod-1, Ribosomal RNA in the case of rrn-1.

Genes with related properties are usually given the same three-letter name and different numbers. For example, the 3 known myosin light chain genes are indicated mlc-1, mlc-2, mlc-3, and the more than 20 different dumpy genes are indicated dpy-1, dpy-2, dpy-3, and so on.

There are no specific recommendations for designating cloned sequences that are not homologous to known genes. Most genomic clones have been provided by the C. elegans mapping/sequencing consortium (based at the Sanger Centre, Cambridge, UK, and the Genome Sequencing Center,...