Figure 3. The KGB-1 pathway regulates expression of kreg genes.

(A, B) Effect of copper ion on expression of kreg-1 (A) and kreg-2 (B). Wild-type and kgb-1 mutant animals were cultured on plates seeded with a bacteria strain. At 3 days after hatching, animals were treated with copper sulfate (1 mM) for 1 hour and total RNA was isolated. Expression of genes was analyzed by qRT-PCR. Data are compared using a one-way ANOVA. **P<0.01. (C) Heavy metal sensitivity caused by inhibition of kreg genes. The eri-1 mutant animals were cultured from embryogenesis on normal plates containing copper sulfate (100 µM) and seeded with bacteria strains expressing the indicated double-stranded RNA. The relative viability is shown with standard errors. Error bars indicate 95% confidence interval. **P<0.01 as determined by Student's t test. (D, E) Effect of copper ion on expression of the kreg-1 reporter. Wild-type and kgb-1 mutant animals harboring the Pkreg-1::venus transgene as an extrachromosomal array were cultured on plates seeded with a bacteria strain expressing the double-stranded RNA for vhp-1. At 3 days after hatching, animals were treated with copper sulfate (1 mM) for 1 hour. These animals were then transferred to NGM plates and incubated for 3 hours. Fluorescent (Venus) views are shown in D. Scale bar: 100 µm. “Weak” refers to animals in which intestinal Venus was present at low levels. “Strong” indicates that Venus was present at high levels in most of the intestine. Percentages of animals in each expression category are listed in E. The numbers (n) of animals examined are shown.