library_construction_protocol: Total RNAs were extracted using TRIzol reagent (Invitrogen, United States USA) according to the manufacturer's protocol. The quantity and quality of total RNA were determined by using the NanoDrop 2000 (Thermo Fisher Scientific, USA) and the Agilent 2100 Bioanaylzer (Agilent Technologies, USA, respectively. Ribosomal RNA of the 12 RNA samples was removed using the Ribo-Zero™ rRNA Removal Kit (Epicentre, USA). RNA libraries were prepared for sequencing using BGISEQ500