Six candidate DEGs were randomly selected for validation by QPCR. Total RNA from independent samples of PP and SP was extracted separately and reverse-transcribed using PrimeScript® RT Reagent Kit with gDNA Eraser (TaKaRa, Dalian, China). The SYBR Green RT PCR assay was carried out in an ABI PRISM 7300 Sequence Detection System (Applied Biosystems). Six pairs of gene-specific primers (IAG, IR, OA receptor, 5-HT receptor 1, Tra-2, and FTZ-F1; Table 1) designed using Premier Primer 5 were used to amplify the partial cDNA gene sequences, respectively. Three biological replicates for each sample and three technical replicates were performed. The β-actin from E. sinensis was chosen as a reference gene for internal standardization . PCR was carried out in a total volume of 10 μl, containing 5 μl of 2x SYBR Premix Ex Taq (TaKaRa, China), 0.2 μl of 50x ROX reference dye, 2 μl of the diluted cDNA mix, 0.2 μl of each primer (10 μM), and 2.4 μl of sterile distilled H2O. The PCR program was 95°C for 5 min, followed by 40 cycles of 95°C for 5 s and 60°C for 31 s. To confirm that only one PCR product was amplified and detected, dissociation curve analysis of amplification products was performed at the end of each PCR reaction. After the PCR program, data were analyzed with ABI7300 SDS software (Applied Biosystems). The relative expression level was calculated using the 2−ΔΔCt method. The results were subjected to one-way analysis of variance (one-way ANOVA) using SPSS 16.0, and P values less than 0.05 were considered statistically significant.