The qRT-PCR analysis was performed on ABI 7500 Real-Time PCR Detection System (Applied Biosystems) using the SYBR® Premix ExTagTM reagent kit (Takara Bio Inc.) according to the manufacturer’s protocol. The PCR reactions were 40 cycles (95 °C for 15 s; 55 °C for 15 s; 72 °C for 20 s) according to the instruction manual. A melting curve was generated to test the specificity of products after the qRT-PCR. The relative expression levels of the selected unigenes were normalized to CfGAPDH gene and calculated using the 2−ΔΔCt method. Data were derived from three independent replicates.