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. 2008 Nov 21;4(11):e1000273. doi: 10.1371/journal.pgen.1000273

Figure 4. Defective basal immune gene expression and p38 MAP kinase activation in the fat-3(wa22) mutant.

Figure 4

Expression of 12 infection- and stress-response genes under normal growth (A) and infection (B) conditions. mRNA expression was quantified by qRT-PCR in wild-type, fat-3(wa22) and sek-1(km4) 1-day-old adults exposed to OP50-1 (A) or PA14 (B) for 12 h. Data are depicted as mean±s.e.m and represent fold expression in mutant animals relative to wild-type under the same conditions, with wild-type set to one. A. Δ, p>0.05 between the fat-3(wa22) and sek-1(km4) mutants; Student's t-test. B. *, p<0.05 between fat-3(wa22) and wild-type; Student's t-test. C–E. Regression analyses of gene expression in uninfected fat-3(wa22) animals compared to null alleles of sek-1(km4) (C), daf-16(mu86) (D) and sma-6(wk7) (E). Analysis included 22 genes with significantly altered basal expression in the fat-3(wa22) mutant relative to wild-type (p≤0.05). Data were compared using Pearson linear regression analysis with best fit and t-tests for statistical analyses. Points represent fold difference in gene expression relative to wild-type animals. F. fat-3(wa22) animals show decreased basal PMK-1 phosphorylation. Immunoblot analysis of PMK-1 activation in uninfected (OP50-1) and infected (PA14) fat-3(wa22) worms compared to wild-type and sek-1(km4) animals. Lysates from age-matched young adult animals exposed to OP50-1 or PA14 for a period of 12 h were analyzed using a monoclonal antibody specific to the doubly phosphorylated activated form of the p38 protein. Arrow on right indicates an additional non-specific band seen with the phospho-p38 specific antibody. Anti-actin antibody was used as loading control. G. Survival analysis of animals exposed to arsenic-induced oxidative stress. One-day-old adult wild-type, sek-1(km4) and fat-3(wa22) animals were placed on plates coated with a final concentration of 3 mM arsenic and survival was monitored every 12 h. Graph depicts fraction of worms alive plotted as a function of time. *, p≤0.001 relative to wild-type; Kaplan Meier non-parametric comparison and a Logrank test.