p38b and JAK-STAT signaling protect against Invertebrate iridescent virus 6 infection in Drosophila
p38b is required for turandot induction and survival A) Mutant strains for the three p38 homologs, p38aMPK1, p38bex9, or p38c1A1, were infected with IIV-6 or injected with PBS, and TotA expression was measured by qRT-PCR 24 hours post-infection. Control genotypes included w1118 and p38bex9/CyO heterozygotes. The results of 3–5 biologically independent replicates are shown. Black bars indicate the mean and error bars represents standard deviation. Statistical analysis, comparing TotA levels in the virus infected control to mutant strains, was determined by two-way ANOVA with Sidak’s correction for multiple comparisons (***p = 0.0004, ** p = 0.0045) B) Kaplan-Meier curves showing survival of homozygous (p38bex9, red lines) or heterozygous (p38bex9/CyO, orange lines) p38b mutant flies following IIV-6 infection (solid lines) or PBS-injected controls (dotted lines) compared to control (w1118, black lines) flies. C) Kaplan-Meier curves showing survival of p38a mutant flies (red lines) following IIV-6 infection (solid lines) or PBS-injected controls (dotted lines) compared to control (w1118, black lines) flies. D) Kaplan-Meier curves showing survival of p38bRNAi expressing (blue lines) or E) p38aRNAi expressing flies (purple lines) following IIV-6 infection (solid lines) or PBS-injected controls (dotted lines). UAS-p38aRNAi and UAS-p38bRNAi flies were crossed to tubulin-GAL4 for ubiquitous knock-down, while the control was generated by w1118 crossed to tubulin-GAL4 (black lines). Statistical significance was determined by Log-rank (Mantel-Cox) test (**** p <0.0001; ns, not significant). A.U., Arbitrary Units. F) Viral loads as determined by QPCR for p38bex9 and p38bex9/CyO heterozygous siblings. Each data point represents 5 flies. Error bars indicate standard error, and black lines indicate the mean. A.U., arbitrary units. Statistics were determined using two-way ANOVA. ns, not significant.