Figure 4: Subtle mutant a178 exhibits robust behavioural phenotypes.

(a) Animals crawling on plate show no locomotive differences (ventral body bends per min), n=20 per genotype. Statistical comparison performed by t-test with a 95% confidence level. Error bars are standard deviation. (b) a178 exhibits normal acetylcholine release according to an aldicarb sensitivity assay. Plot represents fraction of animals moving after transfer to a 1 mM aldicarb NGM plate, n=20 per genotype. Aldicarb assays replicated five times with no differences between genotypes. (c) sax-2 alleles ot10 and ky216 phenocopy the a178 phenotype. Bar plots represent the average phenotype probability of each imaged population, according to the SWLR models built for a178(x0) and a178(x3). Error bars are s.e.m. Statistical comparison performed by t-test with a 95% confidence level and Bonferroni correction for multiple comparisons. Only nonsignificant differences displayed, all other comparisons have P<1e−6. (d) a178 animals display a drastic time-dependent reduction in swimming. Plot represents fraction of animals swimming after transfer to liquid from plate, n=35 per genotype. Replicate experiment with sax-2 alleles in Supplementary Fig. 8. (e) Swimming animals represented as an overlay of segmented images (10 frames, 750 ms, see Supplementary Videos 1–4), two individual worms per genotype and time point.