Worm Breeder's Gazette 11(1): 61
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
In the May '88 WBG (WBG 10(2): 39), I described a screen for mutants whose feeding is abnormal. The collection, still growing, stands as [See Figure 1] The classification is an attempt to make sense of the diversity of phenotypes, and shouldn't be taken too seriously. There is no pair of genes whose mutant phenotypes are not distinguishable. (Well, possibly e2337 and ad462.) I have classified genes as neuronal or non- neuronal depending on whether the mutant feeding behavior looks like something I could phenocopy by killing pharyngeal neurons. In some cases the distinction is clear. For instance, the muscle mutants all show abnormalities in pharyngeal muscle birefringence, and pha-2 has a misshapen pharynx. unc-26 and unc-36 have been shown by mosaic analysis to be necessary in ABp-derived cells for normal locomotion, so the classification of these as neuronal is probably also correct. The apparent bias of X-ray-induced mutations towards slippery pharynx phenotypes is an artefact; I only learned to recognize these recently, and haven't done any EMS mutageneses since. Using the usual implausible assumption of equal mutability for all genes, I estimate there are about 80 genes (42-201 with 95% confidence) that mutate to produce non-lethal feeding abnormalities, about 50 neuronal and 30 non- neuronal. Of these 80, about 30 would be in genes already known because of effects on other behaviors, and 50 would be previously unknown, at least as behavioral genes; some could be essential.