Total RNA was extracted from the tissue using TRIzol® Reagent according the manufacturer's instructions. Then RNA quality was determined by 5300 Bioanalyser (Agilent) and quantified using the ND-2000 (NanoDrop Technologies). Only high-quality RNA sample(OD260/280=1.8~2.2, OD260/230≥2.0, RQN≥6.5, 28S:18S≥1.0, >1μg) was used to construct sequencing library. RNA purification, reverse transcription, library construction and sequencing were performed at ShenZhen BGl Genomics Co., Ltd. (ShenZhen, China) according to the manufacturer's instructions. The RNA-seq transcriptome librariy was prepared following Illumina® Stranded mRNA Prep, Ligation (San Diego, CA) using 1μg of total RNA.