Fig. 3. Phenotypic characterization of ttx-3 and ceh-23 alleles. (A) Thermotaxis assays (see Materials and Methods). Animals were grown at 20°C. Number of assays per genotype: wild type N2=11; ceh-23(ms23)=8; ttx-3(ks5)=6; ttx-3(mg158)=6; ttx-3(ot22)=7; ttx-3(ot23)=8. For each genotype, an average of 284-417 animals were tested per assay. The error bars represent the standard error of the mean. The difference in cryophilic behavior between wild type and ceh-23(ms23) is not statistically significantly different (P>0.3; paired and unpaired Student’s t-test). Our observation of a certain fraction of wild-type animals showing cryophilic behavior is consistent with previous reports (Hedgecock and Russell, 1975; Mori and Ohshima, 1995). (B) Effect of ttx-3 alleles on the level of ttx-3prom::gfp expression in AIY (white arrows point to AIYL/R in different animals). All animals shown contain the integrated ttx-3prom::gfp array mgIs18, which was crossed into the respective mutant backgrounds. In ks5 mutant animals signal strength of mgIs18 is clearly reduced, yet enough freely diffusible GFP protein is made in the cell to allow visualization of the axons. In contrast, mgIs18 expression is mostly undetectable in mg158, ot22, and ot23 mutants. (C) Quantification of the defects shown in B. ‘Dim’ refers to clearly reduced gfp expression with the axons being barely visible, ‘very dim’ to gfp expression that is insufficient to visualize the axons. (D) Dauer assays (see Materials and Methods). Results are from four experiments.
