Large Scale RNA Production Systems (Promega) as described previously (Amparyup et al., 2009). In vivo PmproPO1 and PmproPO2 gene silenced shrimp, plus the GFP dsRNA- and 150 mM NaClinjected shrimp controls, were created as described (Amparyup et al., 2009). Hemolymph was collected from the knockdown and control shrimp at 48 h after the second dsRNA(s) injection. The effi- ciency and specificity of gene knockdown was subsequently veri- fied by means of sq-RT-PCR (Amparyup et al., 2009).