Figure 2.

The immune response induced by bacterial infection is compromised in POSH⁷⁴ mutants. (A) Northern blot analysis of immune response genes, diptericin (dpt) and relish. Total RNA was isolated at an indicated time point after Escherichia coli infection and subjected to northern blot analysis. The inductions of both dpt and relish are significantly delayed compared with those in control flies. Expression of relish is sustained for a longer period in POSH⁷⁴. rRNA, ribosomal RNA. (B–E) Real-time PCR analysis of immune response genes, dpt, relish, attacin A (attA) and puckered (puc). In POSH⁷⁴, induction of dpt is delayed (B), relish expression is sustained for a longer period (C) and induction of attA, the expression of which depends on Relish, is slightly delayed, but its expression level at 4 h after infection is higher than that of the control (D). Expression of puc, a Jun amino-terminal kinase target gene, is delayed and sustained in POSH⁷⁴ (E).