All assays were performed at 20uC unless indicated elsewhere. Qualitative toxicity assays based on visual comparison of worm intoxication were performed on plates with E. coli-expressed Cry5B as described [6, 38] . Beginning with the 4 th larval (L4) stage worms, worms were fed for 48 hours either on control plates with E. coli JM103 that did not express Cry5B (empty vector) or plates prepared with E. coli JM103 expressing Cry5B diluted 1:3 with empty vector transformed JM103. This amount of Cry5B (25%) mildly intoxicates wild-type C. elegans, which allows for identification of strains that are hypersensitive to Cry5B as these strains will be more severely intoxicated than wild type. Quantitative lethal concentration assays were performed as described [38] except the worms were scored after 8 days for Cry5B, CuSO 4 , and tunicamycin. Lethal concentration assays with H 2 O 2 did not include E. coli or 5-fluoro-29-deoxy-uridine, and worms were scored after 4 hours. Concentrations of each toxin were set-up in triplicate for each assay, and each assay was performed independently three times. Purified Cry5B was prepared as described [39] and dissolved in 20 mM HEPES (pH 8.0) prior to use. Approximately 1500 worms were scored for each strain in the calculation of the LC 50 values for each toxin. For tunicamycin assays, the set up was identical to the lethality assay with Cry5B. For the developmental inhibition assay, Cry5B plates were prepared as described [6, 38] . Approximately 100 L1 stage worms (from bleached embryos hatched off overnight) were placed on each plate (60 mm) and the number of worms at the L4 or adult stage 3 days later was determined. This assay was performed independently three times. The P. aeruginosa lifespan assay was performed on slow-killing plates as described [40] , with the following modifications: PA14 was cultured overnight in tryptic soy broth instead of King's broth and then spread on slow-killing plates complemented with 75 uM mM 5-fluoro-29-deoxy-uridine. The experiment was performed three times with approximately 100-150 worms total per strain, at 20uC. To determine if there was rescue of the hypersensitivity phenotype in the intestinal-specific promoter studies, 25% E. coli-expressing Cry5B plates were used to compare Cry5B sensitivities of wild-type N2, xbp-1(zc12), and xbp-1(zc12) that were transformed with constructs to express either green fluorescent protein (GFP) or xbp-1 mRNA within intestinal cells using the app-1 promoter (plasmids are described in Protocol S1). Transgenic L4 stage worms were placed on the 25% E. coli expressing Cry5B plates and their health status was assessed 72 hours later. Specifically, the relative health of each worm was determined qualitatively by comparing body size, darkness of the intestine as an indicator of feeding, and activity, including whether the worm demonstrated spontaneous movement. For scoring of the transgenic worms, comparisons were made using both N2 as a reference for healthy worms, as they demonstrated dark intestines and continuous spontaneous movement, and xbp-1 (zc12) as a reference for intoxicated worms that had pale intestines and demonstrated rare or no spontaneous movement.