Fig 4. Functional assay of spätzle processing enzyme (Tm-SPE) for PLA₂ activity mediation.

(A) Mediation of sPLA₂ activity induced by bacteria and rDSP1 via SPE. (B) Mediation of cPLA₂ activity by bacteria and rDSP1 via SPE. L6 larvae were injected with E. mundtii (2.2 x 10⁵ cells/larvae) or recombinant DSP1 (‘rDSP1’, 0.6 μg/larva). Naïve were injected with PBS. dsRNA specific to SPE or dsCON was injected 24 h before bacteria or rDSP1 injection. At 8 h after E. mundtii or rDSP1 injection, Fatbody and plasma was collected to determine cPLA₂ and sPLA₂ activity, respectively. dsRNA was made from a viral gene (CpBV302). Each treatment was replicated three times. Different letters above standard deviation bars denotes significant difference among means at Type I error = 0.05 (LSD test).