Total RNA was isolated using Trizol reagent (Invitrogen, USA) and Reverse transcriptase-polymerase chain reaction (RT-PCR) was conducted based on the protocol of PrimeScriptTM Total RNA was isolated using Trizol reagent (Invitrogen, USA) and Reverse transcriptase-polymerase chain reaction (RT-PCR) was conducted based on the protocol of PrimeScriptTM Reverse Transcriptase (TaKaRa, Japan)