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Eicosanoids Mediate Insect Nodulation Responses To Bacterial Infections, Jon S. Miller, Tuanh Nguyen, David W. Stanley-Samuelson

Department of Entomology: Faculty Publications

We propose that nodule formation is mediated by eicosanoids in insects. Nodulation is the temporally and quantitatively predominant cellular defense response to bacterial infection in insects and other invertebrates. Inhibition of eicosanoid biosynthesis in larvae of the tobacco hornworn Manduca sexta immediately prior to intrahemocoelic infections with the bacterium Serratia marcescens strongly reduced the nodulation response. Inhibition of eicosanoid biosynthesis also reduced formation of cellular aggregates at 1 hr postinfection, which indicates that eicosanoids mediate early stages of nodulation. Separate treatments with specific inhibitors of phospholipase A₂, cyclooxygenase, and lipoxygenase reduced nodulation, which supports the view that nodule …